# Angle between 90 and 135 degrees.

by Rob
(Seattle)

In triangle ABC, the altitude from B is tangent to the circumcircle of ABC. Prove that
the largest angle of the triangle is between 90 and 135. If the altitudes from both B and
from C are tangent to the circumcircle, then what are the angles of the triangle?

I honestly have no idea!!

### Comments for Angle between 90 and 135 degrees.

 Aug 09, 2011 Angle between 90 and 135 degrees by: Staff ----------------------------------------- Part II Calculating the maximum possible value of ∠A. If point A is moved around the circumcircle away from point B, ∠A becomes larger and larger. (1) Click the following link to VIEW a diagram of how the triangle looks when point A and point B are moved farther apart; or (2A) highlight and copy the link, then (2B) paste the link into your browser Address bar & press enter: Use the Backspace key to return to this page: http://www.solving-math-problems.com/images/circumcircle-triangle-03.png As point A is moved away from point B along the circumcircle, ∠A will continue to increase until point A is located at the bottom of the circumcircle. At this point the points A and C would occupy the same position and the triangle would cease to exist. However, the three angles in the RIGHT TRIANGLE formed by points A, B, and the side “h” triangle would be 90º, 45º, and 45º. This means ∠A = 135º. ∠A cannot actually reach 135º, but it can approach it. Therefore, ∠A must always be larger than 90º, but less than 135º. 90º < ∠A < 135º Thanks for writing. Staff www.solving-math-problems.com