Parts of a Circle (note Pi = 3.14)

Front

What is the formula for the area of a circle?

Back

Area = π × r² (where r is the radius and π ≈ 3.14)

Front

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

Back

The radius is half of the diameter.

Front

If a circle has a radius of 7 cm, what is its diameter?

Back

Diameter = 2 × radius = 14 cm.

Front

What is the circumference of a circle?

Back

Circumference = 2 × π × r (where r is the radius).

Front

If the radius of a circle is 5 inches, what is the area?

Back

Area = π × (5)² = 78.5 square inches.

Front

What is a semi-circle?

Back

A semi-circle is half of a circle, formed by cutting a whole circle along its diameter.

Front

How do you find the area of a semi-circle?

Back

Area of a semi-circle = (π × r²) / 2.

Front

What is the value of π (Pi) approximately?

Back

π ≈ 3.14.

Front

If a circle has a diameter of 20 feet, what is its radius?

Back

Radius = Diameter / 2 = 10 feet.

Front

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

Back

Area = π × (10)² = 314 cm².