Question

The base of an isosceles triangle is 16 cm. If its perimeter is 36 cm ,find its area

Answer 1

let ABC be the isosceles triangle
given,
perimeter=36cm
semi perimeter=36cm/2=18cm
base BC=16cm
now,
perimeter=36cm
=>AB+BC+CA = 36cm
=>AB+16cm+AB=36cm(since ABC is an isosceles triangle)
=>2AB=36cm-16cm
=>AB=20/2
=>AB=10=CA
therefore area of the isosceles triangle
=√s(s-a)(s-b)(s-c)
=√18x(18-10)(18-16)(18-10)cm^4
=√18x8x2x8 cm^2
=2x3x8cm^2
=48 cm^2
hope it's the required answer...