Answer:
The answer in the procedure
Explanation:
step 1
Find the length sides of the triangle
Given the coordinates
A(a1,a2), B(b1,b2) and C(c1,c2)
we know that
the formula to calculate the distance between two points is equal to

so
Calculate
dAB,dBC and dAC
substitute in the formula



step 2
Apply Pythagoras theorem

where
c is the greater side
a and b are the other two sides
substitute the distances in the equation
If the equation is true
therefore
Its a right triangle