CORRECTIONS - Circles TEST

Front

What is the formula for the circumference of a circle?

Back

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

Front

What is the formula for the area of a circle?

Back

Area = π × radius².

Front

If the diameter of a circle is 20 cm, what is the radius?

Back

Radius = diameter / 2 = 10 cm.

Front

What is the value of π (pi) approximately?

Back

π ≈ 3.14.

Front

How do you convert diameter to radius?

Back

Radius = diameter / 2.

Front

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

Back

Circumference = 2 × π × 5 cm ≈ 31.4 cm.

Front

What is the area of a circle with a radius of 7 cm?

Back

Area = π × 7² cm² ≈ 153.94 cm².

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 find the area of a sector?

Back

Area of sector = (θ/360) × π × radius², where θ is the angle in degrees.

Front

What is the relationship between diameter and circumference?

Back

Circumference is directly proportional to the diameter (C = π × D).