Question

what is the semi perimeter of the triangle. whose sides are 4cm , 5cm and 7cm

Answer 1

semi perimeter = half of perimeter

here,

perimeter = 4+5+7=16cm

then 

semi-perimeter=16/2=8cm

i hope this will help you

Answer 2

Perimeter of the triangle = 4 + 5 + 7 
= 16 cm
Semi - perimeter = Perimeter / 2 = 16 / 2 = 8 cm.