- Created by: Cameron Leaf
- Created on: 29-12-09 17:55
Area of shapes can seem a simple topic, but there are formulae you need to learn!
In shapes, area is always measured in mm², cm², m², etc.
Areas of triangles
Lets start with triangles
To work out the area of a three sided shape, use this formula:
B x H ÷ 2
(or 0.5 x B x H)
(B = base, H = height)
Parallelograms are very simple to work out the area of.
You use the same formula that you do for most quadrilaterals:
B x H
Do not confuse the height with the side length of the parallelogram!
Although a kite is a quadrilateral, you have to use a different formula to work out the area:
A x B ÷ 2
(or 0.5 x A x B)
A is usually the width of the kite at its widest part; B is the height of it.
Trapeziums have a strange formula to work out their areas.
It goes like this:
(A+B) x H ÷ 2
(or 0.5 x (A+B) x H)
A = top side length; B = bottom side length