Site icon Noon Academy

Find the area of the triangle formed by joining the mid-points of the sides of the triangle whose vertices are (0, -1), (2, 1) and (0, 3). Find the ratio of this area to the area of the given triangle.

Solution:

Let the triangle’s vertices be A (0, -1), B (2, 1), and C (3, 1). (0, 3).

Let D, E, and F be the midpoints of the triangle’s sides.

D, E, and F coordinates are given by

D .= (0+2/2, -1+1/2 ) = (1, 0)

E = ( 0+0/2, -1+3/2 ) = (0, 1)

F = ( 0+2/2, 3+1/2 ) = (1, 2)

The area of a triangle

   

The area of ΔDEF

   

Area of ΔDEF is 1 square units

The area of ΔABC

   

Area of ΔABC is 4 square units

As a result, 1:4 is the required ratio.