This is a right and scalene triangle with sides 4, 6 and 7.21
Explanation:
One way to solve this problem is to locate the three points of the triangle in the Cartesian plane to have a graphical idea of this triangle. As you can see on the image, this is a rectangle triangle, therefore we can determine with the plane the length of both legs and then with the Pythagorean theorem find out the hypotenuse as follows:
Therefore, we have a triangle with three sides of different length, and that corresponds with a scalene triangle.