Question

Calculate the area and circumference of a circle with diameter 8cm explain by step by step

Answer 1

Area = 50.27 cm²

Circumference = 25.13 cm

Explanation:

The relationship between the diameter and other values of a circle can help us solve for unknown values.

Area

In order to solve for the area, we need to find the radius. The radius is always half of the diameter.

• 8 / 2 = 4

This means that the radius is 4 cm. Then, we can solve for area using the formula, A = πr², where r is the radius. So, plug 4 in and solve. For this calculation, I will not be rounding pi.

• π(4)² ≈ 50.27cm²

Rounded to 2 decimal places, the area of the circle is 50.27cm². If you round pi to 3.14 before doing the calculation, the answer will be 50.24cm².

Circumference

Now, we can solve for circumference. The formula for circumference is C = 2πr, where r is the radius.

• 2π(4) ≈ 25.13 cm

Rounding to 2 decimal places, the circumference of the circle is 25.13 cm. Note that I did not preround pi. If you do preround and use 3.14 for pi, the answer will be 25.12cm.