In triangle ABC with bisector CE, angle A is 55 degrees, angle ABC is 45 degrees. Find angle B.

For a successful solution of the problem, you must firmly know that the sum of the angles in any triangle is 180 °, as well as the property of the bisector to divide the angle in half.

Consider this triangle.

Angle A is 55 ° by condition.

Let us determine the value of the angle ACB, knowing from the condition that CE is the bisector, and the angle ACE = 45 °:

45 * 2 = 90 °;

Determine the value of the angle B:

180 – 55 – 90 = 35 °.