Question

In triangle ABC, the measure of angle CAB is 80° and the measure of angle ABC is 45.5°. What is the measure of angle BCA in degrees? A 125.5°125.5 degrees B 54.5°54.5 degrees C 55.5°55.5 degrees D 64.5°

Answer 1

B 54.5°

Explanation:

Since we have a triangle,

CAB + ABC + BCA = 180 (sum of angles in a triangle)

Since CAB = 80° and ABC = 45.5°, substituting these into the equation, we have

80° + 45.5° + BCA = 180°

simplifying, we have

125.5° + BCA = 180°

collecting like terms, we have

BCA = 180° - 125.5°

BCA = 54.5°

So, the answer is B