Inscribed Circles (Handout J)

Front

What is the formula for the circumference of a circle?

Back

Circumference = 2 × π × r, where r is the radius.

Front

If the radius of a circle is 10 inches, what is the circumference?

Back

Circumference = 2 × 3.14 × 10 = 62.8 inches.

Front

What is the relationship between diameter and radius?

Back

Diameter = 2 × Radius.

Front

If the diameter of a circle is 30 inches, what is the radius?

Back

Radius = Diameter / 2 = 30 / 2 = 15 inches.

Front

What is π (pi)?

Back

π (pi) is a mathematical constant approximately equal to 3.14, representing the ratio of a circle's circumference to its diameter.

Front

How do you find the area of a circle?

Back

Area = π × r², where r is the radius.

Front

If the radius of a circle is 5 inches, what is the area?

Back

Area = 3.14 × 5² = 78.5 square inches.

Front

What is an inscribed circle?

Back

An inscribed circle is a circle that is contained within a polygon and touches all its sides.

Front

How do you find the radius of an inscribed circle in a triangle?

Back

Radius = Area of triangle / (semi-perimeter of triangle).

Front

What is the semi-perimeter of a triangle?

Back

Semi-perimeter = (a + b + c) / 2, where a, b, and c are the lengths of the sides.