Obtuse triangle
An obtuse triangle or obtuse-angled triangle is a type of triangle that has one obtuse (greater than 90°) angle.
As the sum of all the interior angles of a triangle is 180°, an obtuse-angled triangle has one obtuse angle and two acute angles (less than 90° each).
An obtuse triangle is like this:
Practice in the following link, making obtuse triangles with Geogebra
