Question

The difference of semi-perimeter and the sides of triangle abc are 8cm, 7cm and 5cmrespectively. Its semi-perimeter is: options:- a) 10cm b) 5cm c) 15cm d) 20cm

Answer 1

(s-a) = 8
(s-b) =7
(s-c) =5
adding all three,
3s -(a+b+c) = 20

(a+b+c) = perimeter = 2s
⇒3s -2s = 20
⇒s = 20

d) 20 cm