Question

Perimeter of triangle is 120. Side a is 40 and sideb is 30 find the area of triangle

Answer 1

$\bf{\huge{\underline{\boxed{\sf\red{Answer:600\:cm^2}}}}}$

Given :

• Perimeter of triangle = 120 m
• Side a = 40 m and side b = 30 m

To Find :

• Area of triangle

$\huge\underline\green{\tt Solution:}$

→ First of all, find Side ' c '

Perimeter = sum of all three sides

120 = 40 + 30 + c

→ 120 = 70 + c

→ c = 120 - 70

∴ c =  50

Now,

[Let Semi-perimeter be ' S ' ]

$S =\dfrac{40+30+50}{2}$

$S =\dfrac{120}{2}$

∴ S = 60

→ Area of triangle

= $\sqrt{S(S-a)(S-b)(S-c}$

= $\sqrt{60(60-40)(60-30)(60-50)}$

=$\sqrt{60(20)(30)(10)}$

= $\sqrt{60\times 20\times 30\times 10}$

= $\sqrt{360000}$

= 600 cm²

Answer :

Area of the given triangle is 600 cm²