Question

Find area of an isoceles triangle whose sides are 8cm and 10cm.

Answer 1

Since, the triangle is isosceles, the third side will be 8cm or 10cm.
For 8 cm, by heron's formula,
S=
.

=13 cm.
Area=
.

=
.

=
.
Therefore, for,third side=8 cm, area=
.

For, third side =10 cm,
s=(8+10+10)/2
S=14
Area=
.

=
$\sqrt{14 \times 4 \times 4 \times 6}$
=
$4 \sqrt{7 \times 2 \times 3 \times 2}$
=
$8 \sqrt{21}$
Therefore, for, third side =10 cm, area=
$8 \sqrt{21}$