Calculating perimeter and area
Answers are for parents and teachers.
1
A garden 15 m by 24 m is to be fenced with three rows of wire. How many metres of wire are needed?
234
2
A trapezoid has bases 11 cm and 17 cm and height 10 cm. What is its area (cm²)?
140
3
A triangle has area 60 cm² and base 15 cm. How long is the height to that base (cm)?
8
4
Find the area of a circle of diameter 10 cm.
25π cm²
5
Why does the area of a circle become 4 times larger when its radius doubles?
In S = πr² the radius is squared: π(2r)² = 4πr².