Area of Triangle | Gujarati | Fun with Math
Channel: Arvind Gupta
Date: 24/06/2015

With the help of tracing paper and a pen we can find the area of a triangle. Bring a yellow paper and you can see it through the tracing paper. From tracing paper cut a triangle with an extended strip. The three angles of the triangle will be A, B and C. Mark the external angle with double lines. Also mark the point D. First fold a perpendicular from the apex A to the base BC. Open and mark the perpendicular with a pen. Fold the perpendicular in half so that point A sits on the base BC. Mark half the perpendicular as h/2. Cut out the extension as will not need it in this activity. The base of the rectangle will be half base BC or b/2. 

Bring all three vertices of the triangle A, B, C to the point where the perpendicular meets the base. We can see that the area of the rectangle will be base x height (b/2 x h/2 = bh/4). To prove this draw the external boundary of the rectangle on a plane piece of paper. Name this rectangle as PQRS.  Area of rectangle PQRS will be its length x breadth = b/2 x h/2. The area of the triangle will be twice the area of rectangle PQRS, or 2(b/2 x h/2) = bh/2. This can be visually seen in this simple mathematical activity. This work was supported by IUCAA and Tata Trust. This film was made by Ashok Rupner TATA Trust: Education is one of the key focus areas for Tata Trusts, aiming towards enabling access of quality education to the underprivileged population in India. To facilitate quality in teaching and learning of Science education through workshops, capacity building and resource creation, Tata Trusts have been supporting Muktangan Vigyan Shodhika (MVS), IUCAA's Children’s Science Centre, since inception. To know more about other initiatives of Tata Trusts, please visit www.tatatrusts.org