Problema Solution

The perimeter of a triangle with 2 equal sides is 42 cm. If its base were lengthened by 3 cm and each leg were shortened by 5 cm, all 3 sides would be equal. Find the length of the base the original triangle.

Answer provided by our tutors

Lengths of initial triangle

length of two equal sides = X each

Length of base = Y


Since perimeter is 42cm;

X+X+Y = 42

2X+Y = 42 ----(1)



It is given that when base is increased by 3cm and other two shortened by 5cm all lengths will become equal.

Base length of new triangle = Y+3

Length of equal length side = X-5 each


Since they are equal we can say;

X-5 = Y+3

X-Y = 8 ---(2)


(1)-(2)*2

3Y = 26

Y = 26/3




So the base length of original triangle is 26/3cm or 8.667cm.