Help anyone can help me do this question 3,I will mark brainlest.​

see explanation

Step-by-step explanation:

Calculate the slopes between pairs of the 3 points using the slope formula

m =

with (x₁, y₁ ) = (- 9, 3) and (x₂, y₂ ) = (- 3, 9)

m = = = = 1

Repeat with (x₁, y₁ ) = (5, 1) and (x₂, y₂ ) = (- 3, 9)

m = = = - 1

If lines are perpendicular then the product of their slopes = - 1 , then

1 × - 1 = -1

Thus there is a right angle between the 2 lines

Then triangle is right- angled