How do I find the area of a circle C with diameter 14cm?

The formula for the area of a circle is π r2. To use this formula we first need to find r, the radius of the circle. The radius is the distance from the centre of the circle to the edge, and is equal to half of the diameter. The radius of this circle is half of 14, or 14/2 = 7. Now we can use the formula for area.  π x 7= π x 49 = 153.938..... or 159.3 to 1 decimal place. It is important not to forget units with your final answer if they are given in the question, so the area of our circle C = 159.3 cm2.

TH

Related Maths 13 Plus answers

All answers ▸

I am thinking of two numbers. When I add my numbers, the answer is 1 When I multiply my numbers, the answer is 0.09 What are my numbers?


How do you simplify numbers with powers?


The price of a TV is reduced in a sale by 30%. If the sale price is £280 what was the original price?


Solve these two equations simultaneously: 7x+y=1 and 2x^2 - y=3