Question

Find the area of triangle sides of which are 8cm 13cm and 11cm

Answer 1

Answer:

a..8

b..13.

c..11

perimeter..a+b+c

semi perimeter...a+b+c/2

area.√s(s-a)(s-b)(s-c)

Answer 2

Answer:

Area = 43.2cm²

Step-by-step explanation:

a = 8cm

b = 13cm

c = 11cm

Perimeter = 8 + 13 + 11 = 32

∴ Semi-perimeter (s) = 32 ÷ 2

⇒ s = 16cm

Using Heron's formula,

Area = √s (s-a) (s-b) (s-c)

        = √ 16 (16 - 8) (16 - 13) (16 - 11)

        = √16 × 8 × 3 × 5

        = √ 8 × 2 × 8 × 3 × 5

       = 8√2 × 3 × 5

       = 8√30

       = 8 × 5.4

∴ Area = 43.2cm²