An isosceles triangle with angles of 50°, 50° and 80° is an acute-angled triangle. Image caption, A scalene triangle with all angles less than 90° is an acute-angled triangle. A scalene ...

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 ...

Properties of symmetry: - Students may notice symmetry in the isosceles and equilateral triangles and non-symmetry in the scalene triangles Informal recognition of these properties may be helpful in ...