Plot the points A(2, 5), B(–2, 2) and C(4, 2) on a graph paper. Join AB, BC and AC. Calculate the area of ΔABC.
Let the three vertices of triangle ABC be:
A (2, 5), B (-2, 2) and C (4, 2)
Now, when we plot these points in the graph paper then we see that,
Point A and C lie in the quadrant I and point B lie in the II quadrant
Let the line BC intersect y-axis at point D
∴ BC = (BD + DC)
= (2 + 4) units
= 6 units
Now, we have to draw AM perpendicular to x-axis and intersect BC at L
∴ Ordinate of point L = Ordinate of point B - Ordinate of point C
AL = AM – LM
= 5 – 2
= 3 units
Hence, Area of triangle ABC =
=
=
= 9 square units
∴ Area of triangle ABC = 9 square units