In triangle abc, angle c is 90. BC = 20. AB = 25 Find sin B.

Angle C is straight.

It is known that bc = 20, ab = 25.

Find sin b.

sin b = ac / ab;

We calculate the leg of a right-angled triangle ac according to the Pythagorean theorem.

ac = √ (ab ^ 2 – bc ^ 2) = √ (25 ^ 2 – 20 ^ 2) = √ ((25 – 20) * (25 + 20)) = √ (5 * 45) = √ (5 * 5 * 9) = √ (5 ^ 2 * 3 ^ 2) = 5 * 3 = 15;

Calculate sin b.

sin b = ac / ab = 15/25 = 5 * 3 / (5 * 5) = 3/5 = 0.6;

Answer: sin b = 0.6.