Question

What type of triangle is formed by joining the points D(7,3), E(8,1) and F(4,-1)

Answer 1

Calculate the lengths of the sides of the triangle:

The triangle has three different sides, so it's a scalene triangle.

Now if c is the longest side of the triangle, and a and b are the shorter sides, then:

- if , the triangle is right

- if , the triangle is acute

- if , the triangle is obtuse

The longest side is 5.

The square of the longest side is equal to the sum of the squares of the shorter sides, so it's a right triangle.

The triangle is a right scalene triangle.