Question

an isosceles traingle has has perimeter 50 cm and each of the equal sides is 18 cm find the area of triangle​

Answer 1

Given :-

An isosceles triangle has a perimeter OF 50 cm and each of the equal sides is 18 cm

To Find :-

Area

Solution :-

Let the other side be x

${\large{\boxed{\underline{\underline{\dag \bf Perimeter=a+b+c}}}}}$

$\sf :\implies 50=18+18+x$

$\sf :\implies 50=36+x$

$\sf :\implies 50-36=x$

$\sf :\implies 14=x$

Now

Finding semiperimeter

${\large{\boxed{\underline{\underline{\dag \bf Semi-perimeter=\dfrac{1}{2}\times(a+b+c)}}}}}$

$\sf :\implies Semi-perimeter=\dfrac{1}{2}\times 50$

$\sf :\implies Semi-perimeter=25\;cm$

${\large{\boxed{\underline{\underline{\dag \bf Area=\sqrt{s(s-a)(s-b)(s-c)}}}}}}$

$\sf :\implies Area=\sqrt{25(25-18)(25-18)(25-14)}$

$\sf :\implies Area=\sqrt{25(7)(7)(9)}$

$\sf :\implies Area=\sqrt{25\times 49\times 9}$

$\sf :\implies Area=5\times7\times3$

$\sf :\implies Area=105\;cm^2$