Unit 10 Geometry Review - Circles

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

How do you find the radius of a circle if you know the circumference?

Back

Use the formula r = C / (2π), where C is the circumference.

Front

What is the value of π (pi) to two decimal places?

Back

π ≈ 3.14.

Front

If the radius of a circle is 5.2 feet, what is the circumference?

Back

C = 2π(5.2) ≈ 32.7 feet.

Front

What is an arc in a circle?

Back

An arc is a portion of the circumference of a circle.

Front

How do you calculate the length of an arc?

Back

Arc length = (θ/360) × C, where θ is the angle in degrees and C is the circumference.

Front

What is the relationship between the diameter and the radius of a circle?

Back

The diameter is twice the radius: d = 2r.

Front

What is the formula for the area of a circle?

Back

A = πr², where A is the area and r is the radius.

Front

If a circle has a circumference of 12.6 yards, what is the radius?

Back

r = 12.6 / (2π) ≈ 2.0 yards.

Front

What is the measure of a full circle in degrees?

Back

A full circle measures 360 degrees.