Call the attendance
Hook
The Babylonians discovered their own unique form of trigonometry during the Old
Babylonian period (1900-1600BCE), more than 1,500 years earlier than the Greek form.
What is right-angle triangle?
Introduction
A right triangle is a triangle in which one angle is a right angle. The relation between the
sides and angles of a right triangle is the basis for trigonometry. The side opposite the
right angle is called the hypotenuse. The side opposite to angle is called opposite.
Body

Labelling right angle triangles
Exercise 10A.

The trigonometric ratio
Exercise 10B.
Conclusion
Sum up the lesson. Ask students about what they learn.