Explanation:
a) gradient= y2-y1/x2-x1
gradient of AB:
gradient=-4-1/2-3
=-5/-1
=5
gradient of BC:
=-5+4/7-2
=-1/5
b) as the priduct of both gradient is -1 ,both lines are perpendicular.
c) as we have seen lines are perpendicular so it is a right angled triangle.