Question

Fill in the blanks so as to make the following statements true :
The semi perimeter of a triangel is 10 cms. If one of its sides is 5 cms and 7 cms respectively then its third side is________​

Answer 1

semi perimeter = 10 cm
perimeter = 2(10) = 20 cm
let the third side be x

5 + 7 + x = 20
12 + x = 20
x = 8 cm

therefore, its third side is of 8cms