Circles Test Review

Front

What is the formula for the area of a circle?

Back

Area = πr², where r is the radius of the circle.

Front

What is the formula for the circumference of a circle?

Back

Circumference = 2πr, where r is the radius of the circle.

Front

Define a minor arc in a circle.

Back

A minor arc is an arc that is smaller than a semicircle and is named using two endpoints.

Front

Define a major arc in a circle.

Back

A major arc is an arc that is larger than a semicircle and is named using three points, including the endpoints and a point on the arc.

Front

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

Back

The diameter is twice the length of the radius (d = 2r).

Front

How do you find the length of an arc in a circle?

Back

Arc length = (θ/360) × 2πr, where θ is the central angle in degrees.

Front

What is the measure of a full circle in degrees?

Back

A full circle measures 360 degrees.

Front

What is the measure of a semicircle in degrees?

Back

A semicircle measures 180 degrees.

Front

If the radius of a circle is 10 cm, what is the area?

Back

Area = π(10)² = 314.16 cm² (approximately).

Front

If the area of a circle is 78.54 cm², what is the radius?

Back

Radius = √(Area/π) = √(78.54/π) ≈ 5 cm.