An acute angle is less than 90°. A right angle is exactly 90°. An obtuse angle is greater than 90° and less than 180°, a straight line. An isosceles triangle with all angles less than 90° is ...

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 ...