Use Properties of Rectangles, Triangles, and Trapezoids

Question

Find the area of the triangle with base 15 cm and height 18 cm.

Answer 1

Area of a triangle is 1/2 (base x height). A rectangle or square is just base x height. Any triangle can be turned into a quadrilateral by extending the sides until they touch and the “new” triangle will be the same as the old one. This is the reason behind the formula.

so, 1/2 (15 x 18) = 1/2 (270) = 135