Question

if an isosceles triangle has perimeter 40cm. each of equal sides is 14cm. Find the area of the triangle .
​

Answer 1

$\huge\red{Solution :-}$

______________________

Perimeter of isosceles triangle=30cm

Length of equal sides=12cm

Let third side of triangle=xcm

According to problem,

x+12+12=30

x+24=30

x=30−24

x=6

∴ Third side of triangle=6cm

Using Heron's formula

Area of triangle= √s(s−a)(s−b)(s−c) sq. units

where s= a+b+c/2

s= 30/2 =15

Area of triangle= √15(15−12)(15−12)(15−6) cm²

= √15×3×3×9 cm²

=3×3× √15cm²

=9√15cm²

∴ Area of triangle=9√15 cm

.