Question

An isosceles triangle has perimeter 36 cm If each of the equal sides is 10 cm, then the area of the triangle is _______________${\text{cm}}^2$

• A. 48
• B. 28
• C. 38
• D. 26

Answer 1

The correct option is A

48

Let the length of the unequal side be $x$ cm

Then

$10+10+x=36$

$x=16$

We know the altitude bisects the base in an isosceles $△$

$\therefore$ height $AD\left(h\right)=6cm$ $(3-4-5\text{Pythagoras Triplet})$

Area of $△=\frac{1}{2}\times 16\times 6$

=$48c{m}^2$