Circles Word Problems (Circumference, Area, Semicircles)

Front

What is the formula for the area of a circle?

Back

Area = π × r², where r is the radius.

Front

What is the formula for the circumference of a circle?

Back

Circumference = 2 × π × r or Circumference = π × d, where d is the diameter.

Front

If a circle has a diameter of 8 cm, what is its radius?

Back

Radius = Diameter / 2 = 8 cm / 2 = 4 cm.

Front

What is a semicircle?

Back

A semicircle is half of a circle.

Front

How do you find the area of a semicircle?

Back

Area of a semicircle = (π × r²) / 2.

Front

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

Back

Area = π × (5 cm)² = 78.54 square cm.

Front

What is the circumference of a circle with a diameter of 10 cm?

Back

Circumference = π × 10 cm = 31.42 cm.

Front

If the circumference of a circle is 62.83 cm, what is its diameter?

Back

Diameter = Circumference / π = 62.83 cm / π = 20 cm.

Front

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

Back

Area = π × (6 cm)² = 113.10 square cm.

Front

What is the relationship between diameter and radius?

Back

Diameter = 2 × Radius.