Answer:
x = 20
Explanation:
(All triangles have a total length of 180)
x - 2 + 4x + 1 + 4x + 1 = 180
(Use algebra)
x - 2 + 4x + 1 + 4x + 1 = 180
+ 2 - 1 - 1 = + 2 -1 -1
x + 4x + 4x = 180
9x = 180
(divide by 9)
x = 20
Check:
(20) - 2 + 4(20) + 1 + 4(20) + 1
= 180