algebra 1
posted by tyyyyyy on .
The perimeter of a triangle is 72 cenimeters.the second side is twice as long as the first side.the third side is four centimeters shorter than the second side.how long is the first side?

Let the first side length be A, etc.
A + B + C = 72
B = 2A
C = B4
B/2 + B + (B 4) = 2.5 B 4 = 72
2.5 B = 76
B = 30.4
A = 15.2 is the first side length
C = 26.4

Sum = 72, as required