Real World Area and Circumference Flashcard

Front

What is the formula for the area of a circle?

Back

Area = π × r², where r is the radius of the circle.

Front

What is the formula for the circumference of a circle?

Back

Circumference = 2 × π × r or Circumference = π × d, where d is the diameter.

Front

If a circle has a radius of 7 units, what is its area?

Back

154 units² (Area = π × 7² = 154).

Front

If a circle has a diameter of 10 units, what is its circumference?

Back

31.4 units (Circumference = π × 10 = 31.4).

Front

What is the relationship between diameter and radius?

Back

Diameter = 2 × Radius.

Front

If a circular garden has an area of 254.34 square units, what is its radius?

Back

Radius = √(Area/π) = √(254.34/3.14) ≈ 9 units.

Front

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

Back

31.4 feet (Circumference = 2 × π × 5 = 31.4).

Front

How do you find the diameter if you know the circumference?

Back

Diameter = Circumference / π.

Front

What is the area of a circle with a radius of 3 inches?

Back

28.26 inches² (Area = π × 3² = 28.26).

Front

If a tire has a diameter of 27 inches, what is the distance it travels in one rotation?

Back

84.82 inches (Circumference = π × 27 ≈ 84.82).