An obtuse-angled triangle is a triangle in which one of the interior angles measures more than 90° degrees. In an obtuse triangle, if one angle measures more than 90°, then the sum of the remaining two angles is less than 90°.
Special facts about obtuse triangle:
- An equilateral triangle can never be obtuse. Since an equilateral triangle has equal sides and angles, each angle measures 60°, which is acute. Therefore, an equilateral angle can never be obtuse-angled.
- A triangle cannot be right-angled and obtuse angled at the same time. Since a right-angled triangle has one right angle, the other two angles are acute. Therefore, an obtuse-angled triangle can never have a right angle; and vice versa.
- The side opposite the obtuse angle in the triangle is the longest.
In our surroundings, we can find many examples of obtuse triangles. Here are some examples:
- Triangle shaped roofs
- Hangars found in cupboards
Picture Credit : Google
