Question

10. In ABC, if A and B are acute angles, and sin A= 10/13
what is the value of cos A ?

Answer 1

In triangle AB, A and B are acute angles so. AC and BC are right angles.

Sin A = 10/13

13 is the hypotenuse side and 10 is the opposite side.

To find cos A.

From pythagorean theorem:

Explanation: