Question

What is the value of a in the diagram below?​

Answer 1

Answer:

a=8

Step-by-step explanation:

We can use ratios of similar triangles to solve

The smaller triangle has sides a and 12  and the larger triangle has sides a+a+4  and 12+18  which combine to 2a+4  and 30

a               2a +4

--------- = -----------

12            30

Using cross products

30a = 12(2a+4)

30a = 24a +48

Subtract 24a from each side

30a -24a = 24a-24a +48

6a = 48

Divide each sdie by 6

6a/6 =48/6

a =8