In a right-angled triangle ABC, angle A = 90 degrees, side AB = 20cm, AC = 15cm.

In a right-angled triangle ABC, angle A = 90 degrees, side AB = 20cm, AC = 15cm. Find the sin of the angle C, cos of the angle C, tg of the angle C.

1. ВС = √АВ² + АС² = √20² + 15² = √400 + 225 = √625 = 25 cm.

2. Cosine ∠С – quotient of dividing the length of the AC leg, which is one of the sides of this angle, that is, adjacent to it, by the length of the BC hypotenuse:

Cosine ∠C = AC: BC = 15: 25 = 3/5.

3. Sine ∠С – quotient from dividing the length of the leg AB, located opposite this angle, by the length of the hypotenuse BC:

Sine ∠C = AB: BC = 20: 25 = 4/5.

4. Tangent ∠С – quotient of dividing the length of the leg AB, by the length of the leg AC:

Tangent ∠C = 20: 15 = 4/3.