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

In the triangle ABC we find tg A if we know:

Angle C = 90 °;
AC = 12 cm;
CB = 15 cm.
Decision.

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

Hence, we get the formula in the form:

tg a = BC / AC;

We substitute the known values of the legs and calculate what is equal to tg A.

tg A = 15 cm / 20 cm = 15/20 = (5 * 3) / (5 * 4) = (1 * 3) / (1 * 4) = 3/4 = 0.75;

As a result, we got tg A = 0.75.

Answer: tg A = 0.75.