Question

If the sides of a triangle is 20cm,30cm,40cm then it's semi perimeter?

Answer 1

semi-perimeter = a+b+c/2

a=20cm

b=30cm

c=40cm

semi-perimeter =20+30+40/2

                           =90/2

                           =45cm

thus,

semi-perimeter of the triangle is 45cm

Answer 2

$\rm \rightarrowtail \: Semi-Perimeter = \dfrac{a + b + c}{2}$

$\rm \rightarrowtail \: Semi-Perimeter = \dfrac{20 + 30+ 40}{2}$

$\rm \rightarrowtail \: Semi-Perimeter = \dfrac{50 + 40}{2}$

$\rm \rightarrowtail \: Semi-Perimeter = \dfrac{90}{2}$

$\rm \rightarrowtail \: Semi-Perimeter = \cancel \dfrac{90}{2}$

$\\\therefore{ \boxed{ \frak \green{ \: Semi-Perimeter =45cm}}}$