Podcast
Questions and Answers
Which of the following angles is greater than 90 degrees but less than 180 degrees?
A straight angle measures exactly 180 degrees.
True
What is the measure of a right angle?
90 degrees
An angle that measures less than 90 degrees is called an ______ angle.
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Match each type of angle with its corresponding measurement:
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What is the first step to find the radius from the circumference?
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The radius is found by multiplying the diameter by 2.
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If the circumference is 10π cm, what is the radius?
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The formula to calculate the radius from the circumference is r = ______.
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Match the following variables with their meanings:
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What symbol represents parallel lines in a diagram?
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Vertically opposite angles are unequal.
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What do co-interior angles add up to?
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When a transversal crosses two parallel lines, the angles that are equal and can be identified by drawing an 'F' are called _______ angles.
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Match the angle types with their characteristics:
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What type of triangle has two equal sides?
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Scalene triangles have at least two equal sides.
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Name the type of angle that is formed when two lines are crossed by another line, creating angles on the same side that are supplementary.
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An equilateral triangle has all three sides equal and all three angles equal to _____ degrees.
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Match the triangles to their descriptions:
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What type of triangle has all angles measuring less than 90°?
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A right-angled triangle has one angle that measures less than 90°.
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What is the range of angles for an obtuse-angled triangle?
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An acute-angled triangle cannot have any angle measuring _____ degrees.
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Match the following types of triangles with their characteristics:
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Study Notes
Angles
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Types of Angles:
- Acute: Less than 90°
- Right angle: Exactly 90°
- Obtuse: Greater than 90° but less than 180°
- Straight: Exactly 180°
Finding Radius from Circumference
- Formula relationship: $C = πd$
- To find the diameter: $d = \frac{C}{π}$
- To find the radius: $r = \frac{d}{2}$ or $r = \frac{C}{2π}$
- Example: For $C = 10π cm$, radius $r = 5 cm$.
Angles and Parallel Lines
Parallel Lines
- Definition: Lines that never intersect.
- Notation: Denoted with arrows (e.g., AB || CD).
Perpendicular Lines
- Definition: Lines that intersect at a right angle.
- Notation: Represented with a T (e.g., OP ⊥ MN).
Transversal
- Definition: A line that crosses two or more other lines, creating special angle relationships.
Angle Relationships
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Alternate Angles:
- Flipped angles that are equal; identified with a "Z".
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Corresponding Angles:
- Equal angles identified with an "F" pattern.
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Co-interior Angles:
- Angles that add up to 180° when found on the same side of the transversal.
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Vertically Opposite Angles:
- Formed when two lines intersect; these angles are equal (e.g., ∠a = ∠b, ∠c = ∠d).
Classifying Angles in Triangles
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By Sides:
- Scalene Triangle: No equal sides or angles.
- Isosceles Triangle: Two equal sides and angles.
- Equilateral Triangle: All sides and angles are equal (60° each).
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By Angles:
- Acute-angled Triangle: All angles are acute (e.g., 40°, 75°, 65°).
- Right-angled Triangle: One angle is a right angle (90°).
- Obtuse-angled Triangle: One angle is obtuse (e.g., 100°, 40°, 40°).
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
Description
Test your knowledge on different types of angles including acute, right, obtuse, and straight angles. This quiz will help reinforce your understanding of angle classifications and their properties.
