Question 25149
Let x=first side, x+3=second side, and x+3+1=third side.


All together they should total 43.  Therefore:
(x)+(x+3)+(x+3+1) = 43


Remove the parentheses and solve for x.
x+x+3+x+3+1 = 43
3x + 7 = 43
3x = 43-7 = 36
x = 36/3 = 12


x+3 = 12+3 = 15
x+3+1 = 12+3+1 = 16