Final answer:
The measurement of angle B in a triangle with an angle C of 91° can be found by subtracting 91° from 180° to get the sum of angles A and B, which is 89°. To find angle B specifically, more information is required.
Step-by-step explanation:
The question involves finding the measurement of angle B in a triangle with one known angle measurement and two known side lengths. Since the sum of all angles in a triangle is 180 degrees, we can subtract the given angle C (< C = 91°) from 180° to find the sum of the remaining two angles (angle A and angle B). However, we need additional information to find angle B specifically (such as the length of the third side or the measure of angle A). Without this information, we can only state that the sum of angles A and B is 180° - 91° = 89 degrees. Assuming this is a typo, and angle C is 90° (forming a right triangle), angle B can be calculated using trigonometric functions if the lengths of the sides opposite angle B or angle A are known.