Math, asked by rahul1262, 1 year ago

find the area of triangle to side of which are 18 cm and the 10 cm and the perimeter is 42cm

Answers

Answered by IshanS
2
Hi there!

Here,
a = 18
b = 10
c = ?

ATQ,

Perimeter = 42

P = a + b+ c

42 = 18 + 10 + c

42 - 28 = c

c = 14

Using Heron's formula,

S = a+ b + c/2 = P / 2 = 42/ 2 = 21

S - a = 21 - 18 = 3

S - b = 21 - 10 = 11

S - c = 21 - 14 = 7

Area = ✓ S (s- a) (s- b) ( s-c)

= ✓ 21 × 3 × 11 × 7

= 21 ✓ 11 cm²

Hence,
Area of triangle = 21 ✓ 11 cm²

Hope it helps! :D

Cheers,
Ishaan Singh
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