Question

The semi perimeter of a triangle having the lengths of its sides as
20cm, 15cm and 9cm is:​

Answer 1

Step-by-step explanation:

Let a=20cm,b=15cm,c=9cm

And semi-perimeter =S

Now, S=

2

a+b+c

=

2

20+15+9

=

2

44

=22cm

∴ Semi-perimeter of triangle is 22cm.

Answer 2

Answer:

Given sides of the triangle are 20 cm, 15 cm & 9 cm.

We've to find the semi perimeter of the traingle.

By using Formula :

$\star \ \boxed{\sf{\purple{S_{(semi perimeter)} = \dfrac{a + b + c}{2}}}}$

a = 20

b = 15

c = 9

⠀⠀⠀⠀━━━━━━━━━━━━━━━━━━━━━⠀⠀

⠀

☯ Substituting values in the formula ;

$:\implies\sf S = \dfrac{a + b + c}{2} \\\\\\:\implies\sf S = \dfrac{20 + 15 + 9}{2} \\\\\\:\implies\sf S = \dfrac{\cancel{44}}{\cancel{\: 2}}\\\\\\:\implies\boxed{\sf{\purple{S_{(semi perimeter)} = 22}}}$

${\therefore} \: \underline{\sf{Semi perimeter \ of \ the \: \triangle \ is \ 22 \ cm.}}$