Step-by-step explanation:
Let x represent the missing sides measurement.
x+x+28=52
combine like terms
2x + 28 = 52
subtract 28 from both sides
2x + 28 = 52
- 28 - 28
2x = 24
divide both sides by 2
x = 12
plug it back in
one leg is 12 inches
the other leg is 40 inches