Question

Find the third side of the triangle if the semi perimeter is 16 cm and two sides are 8 cm and 11 cm ?​

Answer 1

Answer: Perimeter of triangle is = some of the all side is given =16cm

And given 2 sides = 3.8cm, 5.6cm

Find the third side = 16-(3.8+5.6)

Third side = 6.6 cm

Answer 2

Answer:

Semi - perimeter = perimeter / 2

=>  Perimeter = Semi - perimeter × 2

=> Perimeter = 16 × 2 = 32 cm

Now, let a = 8 cm

b = 11 cm

c = ?

So, perimeter = sum of all sides = a + b + c

=> 32 = 8 + 11 + c

=> 32 = 19 + c

=> 32 - 19 = c

=> c = 13

Hence, the third side (c) is 13 cm.

Hope it helps.