Facts That Matter
AREA OF TRIANGLES
We have already learnt that area of a triangle
[altitude corresponding to that side (or height)]
[altitude corresponding to base (or height)]
Thus, area of a triangle
Unit of measurement for area of any plane figure is taken as square metre (m2) or square centimetre (cm2), etc.
When it is not possible to find the height of the triangle easily and measures of all the three sides are known then we use Heron’s formula, which is given by
Area of a triangle =
where a, b and c are the sides of the triangle and s = semi-perimeter, i.e. half the perimeter of the triangle =
AREA OF AN EQUILATERAL TRIANGLE
Let the side of the equilateral triangle be ‘a’.
⇒ Area of the triangle
Thus, area of an equilateral triangle