To determine if ABC is a right angle triangle, we need to check whether two lines are perpendicular, in other words, an intersection of 90°.
When two lines are perpendicular to each other, then their slope multiplied to give -1
Formula to find steepness slope is vertical distance ÷ horizontal distance
Slope AB = [tex] -\frac{3}{2} [/tex]
Slope BC = [tex] \frac{2}{3} [/tex]
Slope AB is a negative slope while BC is a positive slope
Slope AB × Slope BC = [tex]- \frac{3}{2} [/tex]×[tex] \frac{2}{3} [/tex] = -1
Angle ABC is right angle, hence triangle ABC is a right-angled triangle
