Exact value from special triangle

A question is this type if and only if it asks the student to derive an exact trig value (e.g. sin 60°, cos 45°, cos 30°) from a geometric construction such as an equilateral or isosceles right-angled triangle, without a calculator.

3 questions · Easy -1.8

1.05g Exact trigonometric values: for standard angles

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OCR MEI C2 2006 January Q3

3 marks Easy -1.8

3 Fig. 3 Beginning with the triangle shown in Fig. 3, prove that \(\sin 60 ^ { \circ } = \frac { \sqrt { 3 } } { 2 }\).

OCR MEI C2 2009 June Q1

2 marks Easy -1.8

1 Use an isosceles right-angled triangle to show that \(\cos 45 ^ { \circ } = \frac { 1 } { \sqrt { 2 } }\).

OCR MEI C2 Q9

3 marks Easy -1.8

9 Fig. 3 Beginning with the triangle shown in Fig. 3, prove that \(\sin 60 ^ { \circ } = \frac { \sqrt { 3 } } { 2 }\).