a triangle has a perimeter of 91 centimeters. each of the two longer sides are three times as long as the shortest side. find the length of the three sides

Respuesta :

perimeter = a+b+c

a = short side

b = 3a

c = 3a

a +3a+3a = 91

7a = 91

a=91/7 = 13

short side = 13cm

long sides = 3*13 = 39cm each