Area of Circles & 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

What is the value of π (pi) approximately?

Back

π is approximately 3.14.

Front

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

Back

Use the formula r = √(A/π).

Front

What is the area of a circle with a radius of 5 units?

Back

A = π(5)² = 25π square units.

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

What is the area of a circle with a diameter of 10 units?

Back

A = π(5)² = 25π square units.

Front

If the area of a circle is 16π, what is the radius?

Back

The radius is 8 units.

Front

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

Back

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

Front

What is the area of a circle in terms of pi if the radius is 4 units?

Back

A = 16π square units.