Answer: The correct answer is (b)
Sin A = 3/5 and Cos A = 4/5
Step-by-step explanation: In any right angled triangle, the trigonometric ratios are applied in order to compute the values of any unknown sides or angles. The side labeled the opposite is that side which is facing the reference angle. The reference angle is the one which the question has specified to be used for your calculations. Therefore the reference angle in this question is angle A. The side facing angle A is side CB which is 3 units. Then the side facing the right angle (angle 90) is the hypotenuse which is usually the longest side and in this case it’s side AB which is 5 units. The third line is that which lies between the reference angle and the right angle ( that is, between angles A and C) and that is the adjacent, line AC in this case with a measure of 4 units.
The trigonometric ratios are given as follows;
Sin A = Opposite/Hypotenuse
Cos A = Adjacent/Hypotenuse
Tan A = Opposite/Adjacent
Therefore, Sin A = 3/5 and
Cos A = 4/5
