Geometry Circle Review Area, Circumference

Front

What is the distance around a circle?

Back

Circumference

Front

Is the red line a radius or diameter of the circle?

Back

Diameter

Front

Find the circumference of a circle with a diameter of 28 in (use π ≈ 3.14).

Back

Circumference = π × Diameter = 3.14 × 28 in = 87.92 in (approximately 88 in)

Front

The Jones family wants to enclose their circular garden with a fence. If the radius is 62.5 ft, what is the minimum length of fencing they need to buy?

Back

Circumference = 2 × π × Radius = 2 × 3.14 × 62.5 ft = 392.5 ft

Front

What is the radius of a circle with a circumference of 62.8 ft?

Back

Radius = Circumference / (2 × π) = 62.8 ft / (2 × 3.14) = 10 ft

Front

What is the formula for the area of a circle?

Back

Area = π × Radius²

Front

Calculate the area of a circle with a radius of 7 ft (use π ≈ 3.14).

Back

Area = π × Radius² = 3.14 × (7 ft)² = 153.86 ft²

Front

What is the diameter of a circle if the radius is 9 ft?

Back

Diameter = 2 × Radius = 2 × 9 ft = 18 ft

Front

If a circle has a circumference of 31.4 ft, what is its radius?

Back

Radius = Circumference / (2 × π) = 31.4 ft / (2 × 3.14) = 5 ft

Front

What is the relationship between diameter and radius?

Back

Diameter = 2 × Radius