The base of a triangle is 4 cm greater than the height. The area is 30 cm^2. How do you find the height and the length of the base?

1 Answer
Jan 2, 2017

Height is 6 cm. and base is 10 cm.

Explanation:

Area of a triangle whose base is b and height is h is 1/2xxbxxh.

Let the height of given triangle be h cm and as base of a triangle is 4 cm greater than the height, base is (h+4).

Hence, its area is 1/2xxhxx(h+4) and this is 30 cm^2. So

1/2xxhxx(h+4)=30

or h^2+4h=60

i.e. h^2+4h-60=0

or h^2+10h-6h-60=0

or h(h+10)-6(h+10)=0

or (h-6)(h+10)=0

:.h=6 or h=-10 - but height of triangle cannot be negative

Hence height is 6 cm. and base is 6+4=10 cm.