Question

The semi perimiter of triangle are 10cm.If one of it side is 5cm and 7cm then third side is________.

Answer 1

let the required side be x

5+7+x/2 = 10

12+x = 20

x = 8

Answer 2

Answer:

Let a, B, C be three sides of triangle and S be semi perimeter

S=( a+b+C) /2

10=(5+7+c)/2

20=12+c

20-12=c

8=c

Third side is 8