Circles - Unit 3 IM

Front

What is the radius of a circle?

Back

The radius is the distance from the center of the circle to any point on its circumference.

Front

What is the formula for the circumference of a circle?

Back

C = 2πr, where C is the circumference and r is the radius.

Front

What is the diameter of a circle?

Back

The diameter is the distance across the circle through its center, equal to twice the radius.

Front

How do you calculate the radius if you know the diameter?

Back

Divide the diameter by 2.

Front

What is a semicircle?

Back

A semicircle is half of a circle.

Front

If a circle has a radius of 8 inches, what is its diameter?

Back

The diameter is 16 inches (2 times the radius).

Front

What is the value of π (pi) approximately?

Back

π is approximately 3.14.

Front

If the circumference of a circle is 62.8 inches, what is its radius?

Back

The radius is 10 inches (C = 2πr, so r = C/(2π)).

Front

What is the relationship between radius and diameter?

Back

The diameter is always twice the radius.

Front

What is the circumference of a circle with a radius of 4 inches?

Back

The circumference is approximately 25.12 inches (C = 2πr).