Explanation: Triangles can be classified based on the measures of their angles as follows: 1- Right-angled triangle: Triangle that has one of its angles = 90° 2- Acute-angled triangle: Triangle that has all of its angles less than 90° 3- Obtuse-angled triangle: Triangle that has one of its angles greater than 90°
The attached image shows an obtuse-angled triangle. We can note that measure ∠B is greater than 90°