In triangle ABC, angle C = 90 AC = 12 cm, CB = 15. Find tg A.

Find tg A if it is known:

Triangle ABC – rectangular;
Angle C = 90 °;
AC = 12 cm;
CB = 15.
Solution:

The ratio of the opposite leg to the adjacent leg is equal to the tangent of angle A.

We get the formula:

tg A = BC / AC;

Substitute the known values into the formula.

tg A = 15/12 = (5 * 3) / (4 * 3) = (5 * 1) / (4 * 1) = 5/4 = (4 + 1) / 4 = 4/4 + 1/4 = 1 + 1/4 = 1 + 0.75 = 1.75;

As a result, we got that tg A = 1.75.