It categorizes triangles into equilateral, isosceles, scalene, obtuse, right, and acute based on their sides and angles. The video also covers the concept of congruency, demonstrating how two ...

An isosceles triangle with one angle greater than 90° is an obtuse-angled triangle. An isosceles triangle with angles of 100°, 40° and 40° is an obtuse-angled triangle.

Learn about angles in triangles and quadrilaterals with this BBC Bitesize Maths article. For students between the ages of 11 and 14.