Question

find area of triangle which has two sides is 8 cm and one side is 11 cm and perimeter is 32cm plz answer tomorrow is my online exam by heron's formula class 9

Answer 1

Answer:

let the sides of the triangle be a, b and c

given length of the sides of the triangle are :-

a = 8cm

b = 11cm

c = ?

perimeter of the triangle is given = 32cm

since the sum of all three sides of a triangle is it's perimeter

=> a + b + c = 32cm

=> 8 + 11 + c = 32cm

=> 19 + c = 32cm

=> c = 32 - 19

=> c = 13cm

now we will find the area of the triangle by heron's formula which is √s(s-a)(s-b)(s-c) where s is the semi-perimeter of the triangle.

semi-perimeter of this triangle = 32/2

= 16cm

area of the triangle = √16(16-8)(16-11)(16-13)

= √(16 × 8 × 5 × 3)

= √(2 × 2 × 2 × 2 × 2 × 2 × 2 × 5 × 3)

= 2 × 2 × 2√(2 × 5 × 3)

= 8√30cm²

HOPE THIS HELPS YOU!!

PLZZ MARK AS BRAINLIEST

Answer 2

Answer:

Let x be the unknown side..

Sides = 8cm, 11cm, x cm

Perimeter = 32cm

So third side = 32cm - (11cm+8cm)

= 32cm - 19 cm

= 13cm

Heron's Formula = √s(s-a) (s-b) (s-c)

Value is 's'(semi-perimeter)in heron's formula = (11+8+13)/(2)

= 16

Further steps are with attachments...

Hence the answer is 8√30 cm^2...

Hope this helps....