Discusses the properties and types of triangles, explaining that a triangle is a closed figure with three sides and angles. It categorizes triangles into equilateral, isosceles, scalene, obtuse, right ...

Area of a Right Triangle = A = 1/2 × Base × Height Area of an Equilateral Triangle = A = (√3)/4 × side 2 ...

For right-angled triangles, Pythagoras Theorem can be used to calculate the length of the third side given the lengths of the other two sides. This is revised in section 16.2. For an equilateral ...