Open Up Resources Unit 3 Test Review

Front

What is the definition of the radius of a circle?

Back

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

Front

What is the definition of the diameter of a circle?

Back

The diameter of a circle is twice the length of the radius and is the distance across the circle through its center.

Front

How do you calculate the circumference of a circle?

Back

Circumference = 2 × π × radius or Circumference = π × diameter.

Front

What is the value of π (pi) approximately?

Back

π (pi) is approximately 3.14.

Front

If the radius of a circle is 7 cm, what is the circumference?

Back

Circumference = 2 × π × 7 cm ≈ 43.96 cm.

Front

What is the formula for the area of a circle?

Back

Area = π × radius².

Front

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

Back

Area = π × 5² cm = 25π cm² ≈ 78.54 cm².

Front

What is the relationship between diameter and radius?

Back

The diameter is twice the length of the radius (Diameter = 2 × Radius).

Front

How do you find the area of a circle with a diameter of 10 cm?

Back

First, find the radius (5 cm), then Area = π × 5² cm = 25π cm² ≈ 78.54 cm².

Front

What is the circumference of a circle with a diameter of 12 cm?

Back

Circumference = π × 12 cm ≈ 37.68 cm.