Objective:

To show that the area of a triangle is half the product of the base and the height.

Theory:

Triangle: A triangle is one of the basic shapes in geometry: a polygon with three corners or vertices and three sides or edges which are line segments.

Types of triangles:

Right angled triangle:

A right angled triangle has one of its interior angles measuring 90°. The side opposite to the right angle is the hypotenuse; it is the longest side of the triangle. For  a right angled triangle with sides a, b, c where c is the hypotenuse, a² + b² = c².

Acute angled triangle:

A triangle that has all interior angles measuring less than 90° is an acute triangle or acute-angled triangle. For  an acute-angled triangle with sides a, b, c where  c is the greatest side,   a² + b² > c².

Obtuse angled triangle:

A triangle that has one interior angle that measures more than 90° is an obtuse triangle or obtuse-angled triangle. For  an obtuse-angled triangle with sides a, b, c where  c is the greatest side, a² + b² < c².