Question

Find the missing length. the triangles are similar.

Answer 1

? = 130

Explanation:

I'm letting ? be x

Since the triangles are similar, larger outer and smaller inner, then the ratios of corresponding sides are equal.

If x is the length of side of larger then x - 70 is corresponding length of smaller.

Then

`(x)/(x-70)` =
`(78)/(36)` ( cross- multiply )

78(x - 70) = 36x ← distribute left side

78x - 5460 = 36x ( subtract 36x from both sides )

42x - 5460 = 0 ( add 5460 to both sides )

42x = 5460 ( divide both sides by 42 )

x = 130

Answer 2

70 + 78 + 91 = 239
239 - 42 - 36 = 161