Question

Find the Area of a Triangle whose two sides are 18 cm and 10 cm respectively and the perimeter is 42cm.

Answer 1

Answer:

A ≈ 69.65 cm²

hope it helps ✈

Answer 2

Answer:

${ \large{ \underline { \sf{Solution-}}}}$

Two Sides of Triangle = 18cm, 10cm

Perimeter = 42

Finding Third Side,

We know that sum of all sides is equal to perimeter

${\longrightarrow{\sf{18 + 10 + x = 42}}}$

${\longrightarrow{\sf{28 + x = 42}}}$

${\longrightarrow{\sf{x = 42 - 28}}}$

${\longrightarrow{\sf{ \pmb{x = 14}}}}$

So, Third side = 14cm

Finding S,

${\longrightarrow{\sf{s = \frac{42}{2} }}}$

${\longrightarrow{\sf{ \pmb{s=21}}}}$

Using Formula,

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

By substituting,

${\longrightarrow{\sf{ Area=\sqrt{21(21 - 18)(21 - 10)(21-14} }}}$

${\longrightarrow{\sf{Area= \sqrt{21(3)(11)(7)} }}}$

${\longrightarrow{\sf{ Area=\sqrt{4851} }}}$

${\longrightarrow{\sf{\pmb{Area = 69.64 \: {cm}^{2} }}}}$

Therefore,

• Area of Triangle is 69.64cm²