LET’S TRY ONE
In a right triangle, the side opposite θ is 3, the adjacent side is 4, and the hypotenuse is 5. What is sin(θ)? Give an exact fraction.
sin(θ) = opposite/hypotenuse = 3/5.
Learning steps & teaching tips
Find an exact sine ratio from labeled right-triangle side lengths.
- Identify opposite and hypotenuse relative to the chosen angle before making the ratio.
- Work through the example and explain why each operation is used.
- Estimate or use another method to check the result before choosing.
Try it together
Work with a partner: solve one example, explain the method, then change one number and predict what changes.
Identify opposite and hypotenuse relative to the chosen angle before making the ratio.