Question

2 sides of a triangle is 13cm and 18cm. The perimeter of the triangle is 48cm . What is the third side?

Answer 1

AB+BC+CA=Perimeter of triangle

13+18+CA=48
31+CA=48
CA=17cm

Answer 2

Perimeter of triangle = sum of all sides

48 = 13 + 18 + C

48 - 31 = C

C = 17cm

Hence third side of triangle is 17cm.


Thanks