In triangle ABC, angle C = 15 degrees, point D is marked on the side AC
August 31, 2021 | education|
In triangle ABC, angle C = 15 degrees, point D is marked on the side AC, so that angle ABD = 12 degrees and angle ADB = 80 degrees. Prove that triangle ABC is not right-angled.
The ADB angle is adjacent to the CDB angle, then the ADB angle = (180 – 80) = 100.
The angle BAD of triangle ABD is: BAD = (180 – 100 – 12) = 68.
Then the angle ABC = (180 – 68 – 15) = 97.
Triangle ABC is not rectangular, as required.
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.