Workshop for children who prefer active learning on the topic of trigonometry. This is part 1 on sine ratio.

1. Understanding the triangle
• This part 1:
• Power point for active learning method/ workshop.
• In this power point children will experiment the concept of of sin
ratio.

2. Understanding the triangle
Part 1

3. Objectives
• Making a right angle triangle.
• Find the ratio of the sides of the triangle.
• Measuring sin of the angle

4. Making a right angle
• Take a A4 sheet. Cut into half pieces.
• Take an half piece.

6. • Mark a point in the left bottom
corner of the paper.
• We will call this as origin

7. • Position the protector.

8. • Mark angle 30 degree.

9. • So we have a starting point.

10. • And we have another end point.

11. • Join these two points.

12. • Now we have a straight line at
an angle 30 degree.

13. 1
2
3
1
With adult supervision: Cut the paper
as show in pictures 1,2,3.

14. • Take the triangle and mark the
angle 30 degree in the corner
where you have done your
measurement.

15. • Measuring the triangle’s parameters:
• Look for the 30 degree.
• Measure it’s opposite side
• Measure the adjacent side to 30 degree.
• Measure the hypotenuse

16. Adjacent side
Opposite side
hypotenuse
30°

17. 33
Sample 1 Opposite side Adjacent side Hypotenuse
Note down the values in the table

18. • Now let us reduce the
size of the triangle.
Cut vertically to the
base of the triangle.

19. Fill the second row
Sample 1 Opposite side Adjacent side Hypotenuse
1
2

20. • Again reduce the
triangle size.
Measure all three
parameters of the
triangle.

21. Fill A third row
Sample 1 Opposite side Adjacent side Hypotenuse
1
2
3

22. • Repeat the process until you get five rows.

23. What can you see in the table
• As the adjacent side decreases, the opposite side and hypotenuse
decrease.

24. Break

25. Trigonometry
• Trigonometry is a special and beautiful concept of maths.
• trigonon "triangle" + metron "measure”
• We are going to examine the triangle.

26. • Recall that our triangle has an angle 30 degree. We have an adjacent
side, an opposite side and a hypotenuse.
Adjacent side
Opposite side
hypotenuse
30°

27. Form the table
• As the adjacent side decreases, the opposite side and hypotenuse
decrease.
• Are you interested in
•
𝑂𝑝𝑝𝑜𝑠𝑖𝑡𝑒 𝑠𝑖𝑑𝑒
𝐻𝑦𝑜𝑡𝑒𝑛𝑢𝑠𝑒

28. We are going to check a ratio

29. SINE Ratio
•
𝑂𝑝𝑝𝑜𝑠𝑖𝑡𝑒 𝑠𝑖𝑑𝑒
𝐻𝑦𝑜𝑡𝑒𝑛𝑢𝑠𝑒
• We will call this as sine ratio.
• Go back to the table of the right angle triangle with angle 30 °

30. Checking the Sine ratio for angle 30 °
Opposite side Adjacent side Hypotenuse
Side
Sin 30° =
𝑂𝑝𝑝𝑜𝑠𝑖𝑡𝑒 𝑠𝑖𝑑𝑒
𝐻𝑦𝑜𝑡𝑒𝑛𝑢𝑠𝑒
1
2
3
4
5
Sin 30°

31. Summary
• We took a right angle triangle with an angle 30.
• We measured opposite side and hypotenuses.
• We found their ratio is constant.
• Sine of an angle is the ratio of opposite side to that of hypotenuses.