A triangle may be described by the size of its angles, eg acute-angled, right-angled or obtuse-angled. An acute angle is less than 90°. A right angle is exactly 90°.

An obtuse-angled triangle is a triangle that has one obtuse angle. Acute-angled triangle. In an acute-angled triangle, all three angles are acute. SUBJECTS: Maths. YEARS: 5–6, 7–8.

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 ...