Answer:
base: 22 37/54; sides: 56 17/108
Step-by-step explanation:
If we let x represent half the length of the base, and y represent the length of the side, then we have ...
2x +2y = 135 . . . . . perimeter relation
x^2 +55^2 = y^2 . . . . Pythagorean theorem relation
Solving for y and substituting into the second equation, we have ...
y = 135/2 -x
x^2 + 3025 = (67.5 -x)^2
3025 = -135x +4556.25 . . . . . . expand, subtract x^2
135x = 1531.25 . . . . . . . . . . add 135x -3025
x = 1531.25/135 = 11 37/108
The length of the base is double this value, 22 37/54.
The length of each side is 67.5 -11 37/108 = 56 17/108.
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Check
The perimeter is the base plus two side lengths:
22 37/54 + 2(56 17/108) = (22 +112) +37/54 +17/54 = 134 +1 = 135.