In right angle triangle ABC, 8 cm, 15 cm and 17 cm are the lengths of AB, BC and CA respectively. Then, find out sin A, cos A and tan A.

We have

Given: ∠ABC = 90°, AB = 8 cm, BC = 15 cm and CA = 17 cm

We know sin A is given by,

⇒ [∵, perpendicular is the side opposite to the angle A & hypotenuse is the side opposite to the right angle of that triangle]

⇒ …(i)

Also, cos A is given by

⇒

⇒ …(ii)

Now, tan A can be found out by two ways:

Method 1: tan A is given by,

⇒

⇒

Method 2: tan A can also be written as,

⇒ [from equations (i) & (ii)]

⇒

Thus, , and .