Module 10 Lesson 1 - Circumference and Area

Front

What is the formula for the circumference of a circle?

Back

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

Front

What is the value of π (pi) approximately?

Back

π (pi) is approximately 3.14.

Front

If the radius of a circle is doubled, what happens to the circumference?

Back

The circumference also doubles.

Front

What is the relationship between radius and diameter?

Back

Diameter = 2 × radius.

Front

How do you find the area of a circle?

Back

Area = π × radius².

Front

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

Back

Area = π × 5² = 78.5 cm² (using π ≈ 3.14).

Front

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

Back

Diameter = 2 × 10 cm = 20 cm.

Front

If the circumference of a circle is 31.4 cm, what is the radius?

Back

Radius = Circumference / (2 × π) = 31.4 / (2 × 3.14) = 5 cm.

Front

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

Back

Circumference = π × diameter = 3.14 × 12 = 37.68 cm.

Front

What is the radius of a circle with a circumference of 62.8 cm?

Back

Radius = Circumference / (2 × π) = 62.8 / (2 × 3.14) = 10 cm.