In the triangle ABC, it is known that the angle C is 90 degrees, AB is 9 cm, BC is 3 cm.
March 23, 2021 | education
| In the triangle ABC, it is known that the angle C is 90 degrees, AB is 9 cm, BC is 3 cm. On the hypotenuse AB, point M is marked so that AM: MB is 1: 2. Find CM.
Let the length of the segment AM = X cm, then, by condition, the length of the segment BM = 2 * X cm.
AM + BM = AB.
X + 2 * X = 9.
3 * X = 9.
X = 9/3 = 3.
AM = 3 cm, BM = 2 * 3 = 6 cm.
Let us define the cosine of the angle ABC in the right-angled triangle ABC.
CosABS = BC / AB = 3/9 = 1/3.
In the BCM triangle, we apply the cosine theorem for the triangle.
CM ^ 2 = BC ^ 2 + BM ^ 2 – 2 * BC * BM * CosB.
CM ^ 2 = 9 + 36 – 2 * 3 * 6 * 1/3 = 45 – 12 = 33.
CM = √33 cm.
Answer: The length of the CM segment is √33 cm.
One of the components of a person's success in our time is receiving modern high-quality education, mastering the knowledge, skills and abilities necessary for life in society. A person today needs to study almost all his life, mastering everything new and new, acquiring the necessary professional qualities.