Question

The radius of the circle below is 21 mm.

Calculate the area of the circle.
Give your answer in mm² to 1 d. p.
21 mm

Answer 1

The area of the circle with a radius of 21 mm is approximately 1381.5 mm².

Step-by-step explanation:

To calculate the area of a circle, we can use the formula A = πr², where A is the area and r is the radius. In this case, the radius is given as 21 mm. So, we can substitute r with 21 mm in the formula:

A = π(21 mm)²

A = 3.1415927... × (21 mm)²

A = 3.1415927... × 441 mm²

A ≈ 1381.453 mm²

Rounded to 1 decimal place, the area of the circle is approximately 1381.5 mm².

Answer 2

Answer:The area of a circle can be calculated using the formula:

A = πr²

where A is the area and r is the radius.

Plugging in the given radius of 21 mm, we get:

A = π * 21² = π * 441

A = 441π mm²

To 1 decimal place, 441π can be approximated to 1393.1 mm². So, the area of the circle with a radius of 21 mm is approximately 1393.1 mm² to 1 decimal place.

Step-by-step explanation: