4. Area of a right angled triangle

Now, we shall find the area of the right-angled triangle.

 

Let us consider a rectangle. When we cut a rectangle through the diagonal, we make $2$ right-angled triangles.

 

 

In this right-angled triangle, the base of the angle containing $90^{\circ}$ is considered as base ($b$) $units$, and the other side is considered as height ($h$) $units$.

 

 

Then, the area of the right-angled triangle $ABC$ is given by:

 

$2\times$ Area of the right-angled triangle $=$ Area of the rectangle

 

$2\times$ Area of the right-angled triangle $= l \times b$

 

Area of the right-angled triangle $=\frac{1}{2} (l \times b)$

 

Here, the base and height of the right-angled triangle are the length and breadth of the rectangle, respectively.

 

Therefore, the area of the right-angled triangle is $\frac{1}{2} (b \times h)$$sq. \ units$.