Question

using herons formula find the area of isoceles triangle whose base is b and sides are a

Answer 1

Base of the triangle= b
Sides of the triangle= a
Perimeter of the triangle= a+a+b= 2a+b
Semi perimeter of the triangle=(2a+b)÷2
=a+1/2b
Area of triangle(herons formula)=
$\sqrt{s \times (s - a) \times (s - b) \times (s - c)}$
$\sqrt{(a + \frac{1}{2}b ) \times {(a + \frac{1}{2}b - a ) \times }{(a + \frac{1}{2}b - a ) \times }{(a + \frac{1}{2}b -b ) }}$
$\sqrt{a + \frac{1}{2}b \times \frac{1}{2}b \times \frac{1}{2}b \times a + ( - \frac{1}{2})b }$
$\sqrt{a \times a \times \frac{1}{2} \times \frac{1}{2} \times b \times b}$
$a \times \frac{1}{2} \times b$

1/2ab Ans.