Secondary 3 G2 Mathematics Tutor Bukit Timah | Trigonometric Ratios and Special Angles. Did you know? Some trigonometric values can be found exactly without a calculator.
This Secondary 3 G2 Mathematics tutor guide for Bukit Timah students gives quick explanations and worked examples of trigonometric ratios and special angles. Use the current school syllabus and lesson sequence to select relevant exercises.
SOHCAHTOA
For an acute angle θ in a right triangle, sinθ=opposite/hypotenuse, cosθ=adjacent/hypotenuse and tanθ=opposite/adjacent.
A useful tutoring check is to change one part of the question and ask the learner to explain whether the same method still applies. The first mistaken step is more informative than a final wrong answer.
30-degree values
sin30°=1/2, cos30°=√3/2 and tan30°=1/√3.
A useful tutoring check is to change one part of the question and ask the learner to explain whether the same method still applies. The first mistaken step is more informative than a final wrong answer.
45-degree values
sin45°=cos45°=√2/2, while tan45°=1.
A useful tutoring check is to change one part of the question and ask the learner to explain whether the same method still applies. The first mistaken step is more informative than a final wrong answer.
60-degree values
sin60°=√3/2, cos60°=1/2 and tan60°=√3.
A useful tutoring check is to change one part of the question and ask the learner to explain whether the same method still applies. The first mistaken step is more informative than a final wrong answer.
Worked height
If horizontal distance is 12 m and elevation angle is 45°, vertical rise=12tan45°=12 m.
A useful tutoring check is to change one part of the question and ask the learner to explain whether the same method still applies. The first mistaken step is more informative than a final wrong answer.
Find angle
For opposite=3 and adjacent=4, tanθ=3/4, so θ≈36.9° in degree mode.
A useful tutoring check is to change one part of the question and ask the learner to explain whether the same method still applies. The first mistaken step is more informative than a final wrong answer.
Check
The hypotenuse is the longest side. Check degree mode and whether the result is an angle or length.
A useful tutoring check is to change one part of the question and ask the learner to explain whether the same method still applies. The first mistaken step is more informative than a final wrong answer.
Seven-day revision plan
Day 1: define the quantities and symbols. Day 2: reproduce a worked example with reasons. Day 3: change the values. Day 4: solve a mixed question without a method label. Day 5: repair the first mistake. Day 6: connect the skill with another chapter. Day 7: complete an independent retest.
Frequently asked questions
What should I check first? Identify the question’s given information and requested quantity. How do I verify the answer? Substitute it into the original relationship or diagram. Why might the calculation be correct but the answer wrong? A mistaken reference point, denominator or unit can change the question being answered.
Official syllabus and small-group tutorial context
Consult the 2027 SEC G2 Mathematics K210 syllabus for exact assessment scope. The unchanged eduKateSG three-pupil Mathematics tutorial reference describes the existing learning model near Sixth Avenue. Confirm current Secondary 3 G2 tutor, class suitability, fees, venue and timetable directly.
Related Secondary 3 G2 Mathematics guides
Read Angles of Elevation and Depression, Probability Rules and Linear Graph Intersections.