In a triangle,middle length side is 3more then shortest side, and the longest side is double middle length side.perimeter is 45 cm. side lengths are?
If the length of the shortest side is x, then the length of the middle side is x + 3 and the length of the longest side is 2(x + 3). The perimeter is the sum of the lengths of all sides, so
x + (x+3) + 2(x+3) = 45
Opening the parenthesis and simplifying the left side,
4x + 9 = 45
4x = 36
x = 9
x + 3 = 12
2(x + 3) = 24
The lengths of the sides are, shortest to longest, 9, 12, and 24.