GEO 11.2 - Area of Circles and Sectors

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

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

Back

Use the formula r = √(A/π).

Front

If the area of a circle is 706.9 square inches, what is the radius?

Back

The radius is approximately 15 in.

Front

What is the area of a circle with a radius of 10 inches?

Back

A = π(10)² = 100π ≈ 314.16 square inches.

Front

What is the area of a circle with a radius of 7 inches?

Back

A = π(7)² = 49π ≈ 153.94 square inches.

Front

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

Back

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

Front

What is a sector of a circle?

Back

A sector is a portion of a circle enclosed by two radii and the arc between them.

Front

How do you calculate the area of a sector?

Back

Area of sector = (θ/360) × πr², where θ is the angle in degrees.

Front

If a circular table top has an area of 324 square inches, what is the radius?

Back

The radius is approximately 10.2 in.

Front

What is the area of a circle with a diameter of 14 inches?

Back

A = π(7)² = 49π ≈ 153.94 square inches.