In an isosceles triangle ABC with base AC, the side AB is 25, and the height drawn to the base is 20.
| June 12, 2021 | education
In an isosceles triangle ABC with base AC, the side AB is 25, and the height drawn to the base is 20. Find the cosine of angle A.
In a right-angled triangle ABH, according to the Pythagorean theorem, we determine the length of the leg AH.
AH ^ 2 = AB ^ 2 – BH ^ 2 = 625 – 400 = 225. AH = 15 cm.
Then CosA = AH / AB = 15/25 = 3/5.
Answer: The cosine of angle A is 3/5.
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.
