Real World Area and Circumference Flashcard

Front

What is the formula to calculate the circumference of a circle?

Back

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

Front

If the circumference of a circle is known, how can you find the radius?

Back

Radius = Circumference / (2 × π).

Front

What is the relationship between diameter and radius?

Back

Diameter = 2 × radius.

Front

How do you calculate the area of a circle?

Back

Area = π × radius².

Front

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

Back

Diameter = 2 × 10 cm = 20 cm.

Front

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

Back

Radius = 31.4 cm / (2 × π) ≈ 5 cm.

Front

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

Back

Circumference = π × 12 cm ≈ 37.68 cm.

Front

How much more length is needed to complete a semi-circle if the straight edge is already built?

Back

Length needed = (π × radius) / 2.

Front

What is the area of a circle with a diameter of 8 cm?

Back

Area = π × (4 cm)² ≈ 50.27 cm².

Front

If the diameter of a circular object is 14 mm, what is its circumference?

Back

Circumference = π × 14 mm ≈ 43.98 mm.