Answer: Angle A = 53.9 degrees
Step-by-step explanation: We have a right angled triangle with two sides clearly given and one angle to be calculated. If the angle to be calculated is angle A, then having angle A as our reference angle, line AC (10 units) is the adjacent, line CB is the opposite while line AB (17 units) is the hypotenuse. Having been given the adjacent and the hypotenuse, we can now use the trigonometric ratio as follows;
CosA = adjacent/hypotenuse
CosA = 10/17
CosA = 0.5882
By use of the calculator or table of values,
A = 53.97
Approximately to the nearest tenth,
A = 53.9 degrees
