Question

how many metres of wire is needed to fence a circular pond of radius 7.7m if the fence is to have three strands of wire all the way around .Give your answer correct to one decimal place. (Take pi is 3.14)​

Answer 1

Find the circumference of the pond:

Circumference = 2 x pi x radius

Circumference = 2 x 3.14 x 7.7 = 48.356 m

You want to go around 3 times so multiply the circumference by 3:

48.356 x 3 = 145.068m

Rounded to 1 decimal = 145.1m