Question

find area of a triangle whose perimeter is 168 cm and two of its sides are 56 cm and 60 cm​

Answer 1

Area of triangle = 1344cm²

how's my writing?

Answer 2

Perimeter = 168cm

a = 56cm

b = 60cm

c = ?

Perimeter = a+b+c

56+60+c = 168cm

116 + c = 168cm

c = 168-116 = 52cm

S = a+b+c/2

S = 56+60+52/2 = 168/2 = 84cm

Using Herons Formula,

Area of ∆ =

$\sqrt{s(s - a)(s - b)(s - c)}$

$\sqrt{84(84 - 56)(84 - 60)(84 - 52)}$

$\sqrt{84(28)(24)(32)}$

$= {1344cm}^{2}$