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

##### 1 Answer

Oct 1, 2016

A right-angled triangle is formed.

#### Explanation:

1) calculate d the distance between the points of the triangles, use the distance formula :

Pythagorean theorem :

The theorem states that: The sum of the squares of the lengths of the legs of a right triangle is equal to the square of the length of the hypotenuse.

Now we use the theorem to check and see if the triangle is right-angled or not :

As