The perimeter of an isosceles triangle is 36 centimeters and two sides of the triangle are in the ratio $2:7$. What is the number of centimeters in the length of the longest side?
Since it asks for the longest SIDE , I will assume the sides are in ratio 2:2:7 and NOT 2:7:7 (because then it would have TWO long sides)
36/(2+2+7) * 7 = 22.9 cm
2:7:7
2x + 7x +7x = 36
x = 2.25
The length of the longest side is 15.75