Circles: Area & Circumference

Front

What is the diameter of a circle?

Back

The diameter is the distance across a circle through its center, equal to twice the radius.

Front

What is circumference?

Back

Circumference is the distance around a circle.

Front

What is the formula for the circumference of a circle?

Back

Circumference = π × diameter or Circumference = 2 × π × radius.

Front

What is the radius of a circle?

Back

The radius is the distance from the center of the circle to any point on its circumference.

Front

What is the area of a circle?

Back

The area is the space inside the circle, calculated using the formula: Area = π × radius².

Front

How do you calculate the area of a circle with a radius of 4 cm?

Back

Area = π × (4 cm)² = 50.24 cm².

Front

If a circle has a diameter of 10 inches, what is its radius?

Back

The radius is 5 inches (half of the diameter).

Front

What is the relationship between diameter and radius?

Back

The diameter is twice the radius.

Front

How do you find the area of a circular pizza with a 10-inch diameter?

Back

First, find the radius (5 inches), then use the formula: Area = π × (5 inches)² ≈ 78.54 in².

Front

What is the area of a square pizza with a side length of 9 inches?

Back

Area = side × side = 9 in × 9 in = 81 in².