Parallelograms - base or height

You now know how to find the area of a parallelogram, but what happens if you need to find the base or the height? You just have to rearrange the formula.

A = b \times h

h={A}\div{b} or h=\frac{A}{b}

b={A}\div{h} or b=\frac{A}{h}


The area of this parallelogram is \text{12 cm}^2. What is its perpendicular height?

Area of a parallelogram diagram

h = A \div b

h = 12 \div 4 = 3~cm


Find the length of the base of this parallelogram:

Area of a parallelogram diagram

b = A \div h

b = 40 \div 5 = 8~cm

Remember to divide the area by the perpendicular height.