Question

Find the missing length of the triangle.

Answer 1

The missing value is 12

Answer 2

There are special properties to certain right triangles.

A 3-4-5 triangle will always be a right triangle. 9 divides into 3, and 15 divides into 5, so you can use ratios to find b.

Since 9 divides into 3, we will use this to set up proportions for the missing value:

$\frac{9}{3} = \frac{b}{4}$

Cross multiply the fractions.

$3b = 36$

Divide both sides by 3.

$b = 12$

The missing value is 12.