Question

Find the area of a circle with radius 5mm, rounded to the nearest tenth. A. 15.7mm2 B. 31.4mm2 C. 78.5mm2 D. 246.7mm2

Answer 1

1. The Formula to getting the area of a circle is pi r^2= 3.14 times the radius squared. Plug in the number given in the question to get your answer.
2. The Circumference formula is 2pir which is 2 time 3.14 times the radius given. Plug in the number to get your answer.
3. This one is giving you the diameter, therefore you need to divide the diameter by 2 to get the radius (diameter is twice the size of radius) and plug in the radius into the first formula (3.14 times r^2) to get your answer.