Question

a triangle with a base of 6cm and a height of 8cm is similar to a triangle with base 21cm. What is the height of the second triangle

Answer 1

Make a proportion.

Do base over height;
`(base)/(height)`.


`(6)/(8) = (21)/(h)`
h is the height of the second triangle. Solve for h.

Cross multiply.

`(6)/(8) = (21)/(h)`
6h = 168
h = 28

The height of the second triangle is 28 cm.