Question 156936
Let one of the sides be "x"; Let the other side be "28-x'

Use Pythagoras to find "s" and 28-x:

EQUATION:
x^2 + (28-x)^2 = 20^2
x^2 + 784 - 56x + x^2 = 400
2x^2 -56x + 384 = 0
x^2 - 28x + 192 = 0
(x-12)(x-16) = 0
x = 12 or x = 16
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Cheers,
Stan H.