Questions and Answers
What is the term used to describe the distance around a circle?
What is a characteristic of a regular polygon?
What is the formula to find the perimeter of a regular polygon?
What is the meaning of the prefix 'peri-' in the word perimeter?
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What type of polygon is a square?
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What units are used to measure perimeter and circumference?
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What is an irregular polygon?
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What is the formula to find the perimeter of an irregular polygon?
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What is the perimeter of an equilateral triangle with a side length of 9 units?
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What is the perimeter of a square with a side length of 6 units?
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What is the formula to find the perimeter of a rectangle?
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What is the circumference of a circle with a radius of 12 units?
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What is a characteristic of an equilateral triangle?
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What is a type of irregular polygon?
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What is the center of a circle?
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Study Notes
Perimeter and Circumference
- Perimeter is the measure of the distance or path around a 2D geometric shape, particularly polygons.
- Polygons are closed, 2D shapes with at least three straight sides and three angles.
- Circles are not considered to be polygons, and the distance around a circle is called the circumference.
- Perimeter and circumference both measure the distance around a geometric shape and are measured in linear units (e.g., inches, feet, meters, kilometers).
Types of Polygons
- Regular polygons are equilateral and equiangular, meaning all sides are equal in length and all angles are equal in measure.
- Irregular polygons are not regular, meaning they are not equilateral or equiangular.
- Examples of regular polygons include squares and equilateral triangles.
- Examples of irregular polygons include concave polygons with unequal sides and angles.
Finding Perimeter
- The formula for finding the perimeter of a regular polygon is P = n * a, where n is the number of sides and a is the length of one side.
- The universal formula for finding the perimeter of any polygon (regular or irregular) is P = ∑_side lengths.
- The formula can be used to find the perimeter of irregular polygons, such as concave L-shaped polygons.
Perimeter of Specific Shapes
- The perimeter of an equilateral triangle is found by multiplying the length of one side by 3 (P = 3 * s).
- The perimeter of a square is found by multiplying the length of one side by 4 (P = 4 * s).
- The perimeter of a rectangle is found by adding the length and width, and then multiplying by 2 (P = 2 * (l + w)).
Circumference of a Circle
- The circumference of a circle is found using the formula C = 2 * π * r, where r is the radius of the circle.
- The radius is the distance from the center of the circle to any point on the circle's outline.
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Description
Learn about the definition and concept of perimeter in geometry, how it differs from circumference, and its relation to polygons and circles.