Question

Find the area of an isosceles triangle one of whose equal sides is 5 units and base 6 units in sq units

• A. 10
• B. 12
• C. 13
• D. 15

Answer 1

The correct option is B 12

Since the height of the triangle, divides it into two right angled triangles,
$a^2=h^2+{\left(\frac{b}{2}\right)}^2$
$=>5^2=h^2+3^2$
$h^2=25-9=16$
$h=\sqrt{16}=4$ units
Area of triangle $=\frac{1}{2}\times base\times height=\frac{1}{2}\times 6\times 4=12$ sq units