Questions and Answers
What are special right triangles?
special right triangles
What ratios can be used to find the missing side lengths of a 45-45-90 triangle?
Refer to the provided image.
What are the lengths of sides a and b in the triangle?
a = 5 ft, b = 5 ft
What are the lengths of sides b and c in the triangle?
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What are the lengths of sides a and b in the triangle?
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What is the sine of angle a?
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What is the cosine of angle a?
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What is the tangent of angle a?
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What ratios can be used to find the missing side lengths of a 30-60-90 triangle?
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What are the lengths of sides a and b in the triangle?
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What are the lengths of sides a and b in the triangle?
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What are the lengths of sides b and c in the triangle?
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What are the sine values of the 30-degree angle and the 60-degree angle?
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What are the cosine values of the 30-degree angle and the 60-degree angle?
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What are the tangent values of the 30-degree angle and the 60-degree angle?
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What is the sine of the 30 angle and the sine of the 60 angle?
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What is the cosine of the 30 angle and the cosine of the 60 angle?
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What is the measure of a 75° angle in radians?
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What is the measure of a 135° angle in radians?
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If an angle measures 5π/4 radians, what is the measure in degrees?
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Which angles are coterminal with a 140° angle? Select all that apply.
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Which angles are coterminal with a 30° angle? Select all that apply.
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What is the tangent of the angle?
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What is the sine of the angle?
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What is the cosine of the angle?
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What is the measure of an angle in standard position that has a terminal side from the origin to point E?
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Which point forms a terminal side with the origin that creates an angle with a sine of 0 and a cosine of -1?
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Which point forms a terminal side with the origin that creates an angle with a sine of 1/2 and a cosine of √3/2?
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What is the tangent of the angle?
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What is the measure of an angle in standard position that has a terminal side from the origin to point i?
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Which statements are true regarding the trigonometric ratios of this triangle? Select all that apply.
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What are the special right triangles mentioned in lesson 12?
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What are the correct ratios for a 45-45-90 triangle?
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If the lengths of sides a and b are both 5 ft, what type of triangle is it?
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What are the lengths of sides b and c if b = 3 in?
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What are the lengths of sides a and b if a = √2/2 m?
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What is the sine of angle a at 45 degrees?
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What is the cosine of angle a at 45 degrees?
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What is the tangent of angle a at 45 degrees?
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What are the correct ratios for a 30-60-90 triangle?
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If a = 8√3 in, what is the length of side b in a 30-60-90 triangle?
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If a = 1/2 cm in a 30-60-90 triangle, what is the length of side b?
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If b = 7 ft, what is the length of side c in a right triangle?
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What is the sine of the 30-degree angle?
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What is the sine of the 60-degree angle?
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What is the cosine of the 30-degree angle?
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What is the cosine of the 60-degree angle?
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What is the tangent of the 30-degree angle?
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What is the tangent of the 60-degree angle?
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What angle corresponds to 𝝅 radians?
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What is the measure of angle acd in radians?
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If o equals 45°, what is the measure of arc ab in radians?
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What is the measure of a 75° angle in radians?
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What is the measure of a 135° angle in radians?
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If an angle measures 5𝝅/4 radians, what is the measure in degrees?
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If an angle measures 2𝝅/9 radians, what is the measure in degrees?
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Which angles are coterminal with a 140° angle? (Select all that apply)
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Which angles are coterminal with a 95° angle? (Select all that apply)
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Which angle is coterminal with an angle that measures 𝝅/4 radians?
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Which angle is coterminal with an angle that measures 2𝝅/3 radians?
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If an angle measures 6𝝅/5 radians, what is the measure in degrees?
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Which angles are coterminal with a 30° angle? (Select all that apply)
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What is the radian measure of positive angle acb?
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What point forms a terminal side that creates an angle with a sine of 0 and a cosine of -1?
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What is the tangent of the angle represented by (1/2, -√3/2)?
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What is the sine of the angle represented by (-√3/2, 1/2)?
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Use reference angles to find the sine of 210°.
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Use reference angles to find the cosine of 210°.
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Use reference angles to find the tangent of 225°.
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What mistake did Yelenia make, if any?
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What is the best critique of Thomas's proof?
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If angle o has a terminal side in quadrant ii and sin(o) = 24/25, what is cos(o)?
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From the previous question, what is tan(o)?
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If angle o has a terminal side in quadrant iii and cos(o) = -4/5, what is tan(o)?
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Study Notes
Special Right Triangles
- Key formulas for 45-45-90 triangles: sides are in the ratio 1:1:√2.
- For a 45-45-90 triangle with each leg of length 5 ft, hypotenuse is 5√2 ft.
- In a 30-60-90 triangle, the sides are in the ratio 1:√3:2.
- Example dimensions: for 30-60-90 triangle with shorter leg of 3 in, the longer leg is 3√3 in, and the hypotenuse is 6 in.
Trigonometric Functions
- Sine, cosine, and tangent for angle 45°: sin(45°) = cos(45°) = √2/2 and tan(45°) = 1.
- For angle 30°: sin(30°) = 1/2, cos(30°) = √3/2, tan(30°) = √3/3.
- For angle 60°: sin(60°) = √3/2, cos(60°) = 1/2, tan(60°) = √3.
Radian Measure
- A full circle is 2π radians; hence angle acf at 3/4 of a circle measures 3π/4.
- π radians corresponds to a 180° angle; angles can be converted between degrees and radians using multiplication by (π/180) or (180/π).
- Examples: 75° = 5π/12 radians and 135° = 3π/4 radians.
Coterminal Angles
- Angles that share the same terminal side can be found by adding or subtracting multiples of 360° or 2π radians.
- Examples of coterminal angles for 140°: 500°, 580°; for 95°: 815°, -265°.
Quadrants and Reference Angles
- Reference angles help find the sine, cosine, and tangent for angles in different quadrants.
- In quadrant II: sin(120°) = √3/2, cos(120°) = -1/2, tan(120°) = -√3.
- In quadrant III: sin(210°) = -1/2, cos(210°) = -√3/2, tan(210°) = √3/3.
Pythagorean Identity
- The identity states that sin²(o) + cos²(o) = 1 holds true for any angle.
- Example: if sin(o) = 24/25, then cos(o) = -7/25 based on sinusoidal relationships defined by the unit circle.
Unit Circle Properties
- The unit circle relates the sine and cosine of angles to coordinates of points (x, y) where x = cos(θ) and y = sin(θ).
- The distance of a point from the origin (1 in the unit circle) relates to hypotenuse definition in sine and cosine: sin(θ) = opposite/hypotenuse, cos(θ) = adjacent/hypotenuse.
Angle Conversions
- Angle conversions between degrees and radians involve multiplying the degree measure by π/180.
- Example conversions: 6π/5 radians = 216° and 5π/8 radians = 112.5°.
Key Values of Trigonometric Functions
- Common angles have defining sine and cosine values:
- sin(45°) = √2/2
- sin(225°) = -√2/2, cos(225°) = -√2/2, tan(225°) = 1.
General Conclusions
- Understanding special right triangles, angles in both degree and radian measures, and properties of the unit circle are fundamental in trigonometry.
- Mastery of reference angles and trigonometric identities aids in solving a variety of problems related to angles and triangles.
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Description
This quiz covers special right triangles, including the properties and ratios of 45-45-90 triangles. Examine key definitions and apply them to determine side lengths in various scenarios. Test your understanding of trigonometric principles presented in this unit.