Question

An isosceles triangle has perimeter 30 cm and each of its equal......​

Answer 1

Answer:

(a)

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Answer 2

$\color{red}\huge{\underline{\underline{GIVEN\dag}}}$

• $perimeter = 30cm$
• $equal \: sides = 12cm$

$\color{red}\huge{\underline{\underline{SOLUTION\dag}}}$

Let the 3rd side be 'x'

$12 cm+ 12cm + x = 30$

$x = 30cm - 24cm$

$\therefore x = 6cm$

By HERON'S FORMULA,

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

Where,

• $\bf \: s = \frac{sum \: of \: all \: sides(perimeter)}{2}$
• $\bf a, \: b \: ,c \: \: are \: \: the \: \: sides \: \: of \: \: triangle$

Here;

$s = \frac{30}{2}$

$s = 15$

$a = 12$

$b = 12$

$c = 6$

$\implies \sqrt{15(15 - 12)(15 - 12)(15 - 6)}$

$\implies \sqrt{15 \times 81}$

$\orange{ \bf \boxed{\therefore \bf area = 9 \sqrt{15} {cm}^{2} }}$

HOPE THAT HELPS!!