Introduction to Trigonometry

Gap-fill exercise

  
Fill in all the gaps, then press "Check" to check your answers. Use the "Hint" button to get a free letter if an answer is giving you trouble. You can also click on the "[?]" button to get a clue. Note that you will lose points if you ask for hints or clues!
An equation involving trigonometric ratios of an angle is called a .

The values of trigonometric for angles 0°, 30°, 45°, 60° and 90°.

If one of the trigonometric ratios of an angle is known, the remaining trigonometric ratios of the angle can be easily determined.

The value of sin A or cos A never exceeds 1, whereas the value of sec A or cosec A is always or equal to 1

sin (90° – A) = .

cos (90° – A) = .

tan (90° – A) = .

cot (90° – A) = .

sec (90° – A) = .

cosec (90° – A) = .

cosec A = 1/ .

sec A = 1/.

tan A = 1/.

tan A = /cos A .

cos A = (side adjacent to angle A)/().

Reciprocal of cot A is .

Reciprocal of cosec A is .

If sin A = cos A, 0° < A < 90°, then A is equal to °.

If cos (40° + A) = sin 30°, the value of A is °.