Answer:
x = 25
Explanation:
This is a similar triangle problem
Therefor two sides of triangle A are in the same proportion as two sides of triangle B
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Triangle A
Short leg = x
Long leg = 60
proportion = x/60
Triangle B
Short Leg = 60
Long leg = 144
proportion = 60/144
Therefor
x/60 = 60/144
multiply both sidees by 60
x = 60*60/144
x = 25