Question

Find the missing length indicated.

Answer 1

28

Explanation:

Looking at the figure you can see two triangles

The outer triangle has sides of 35, 15 and a base of unknown length

The inner triangle has sides of ?, 15 - 3 = 12 and a base of unknown length

The bases are parallel to each other

So the two triangles are similar

Therefore their side proportionalities are the same for all sides

This means

`(?)/(35) = (12)/(15)\\\\`

Cross-multiplying,

`? = 35 * (12)/(15)\\\\? = 28`