The sides of the triangle are 3x, 4x and 5x
3x + 4x + 5x = 90
12x = 90
x = 90/12
x = 7.5
first side = 3x = 3 * 7.5 = 22.5 cm
second side = 4x = 4 * 7.5 = 30 cm
third side = 5x = 5*7.5 = 37.5 cm
i'm not sure how to solve the first one but the second is 150
Answer: 1 and 3/70
Explanation: Find the least common denominator and then combine like terms. The LCM is 70.