5.2 - Circumference and Area

Front

What is the formula for the area of a circle?

Back

Area = πr², where r is the radius.

Front

What is the formula for the circumference of a circle?

Back

Circumference = 2πr, where r is the radius.

Front

What does π (pi) represent?

Back

π is a mathematical constant approximately equal to 3.14.

Front

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

Back

Area = π(7)² = 49π cm².

Front

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

Back

Circumference = 2π(7) = 14π cm.

Front

What is the relationship between diameter and radius?

Back

Diameter = 2 × Radius.

Front

If the diameter of a circle is 18 cm, what is the radius?

Back

Radius = Diameter / 2 = 18 / 2 = 9 cm.

Front

What is the area of a circle with a radius of 9 cm?

Back

Area = π(9)² = 81π cm².

Front

What is the circumference of a circle with a radius of 9 cm?

Back

Circumference = 2π(9) = 18π cm.

Front

How do you convert the circumference to diameter?

Back

Diameter = Circumference / π.