Given that the measure of angle
𝐴𝑂𝐵 equals 75 degrees, what is the measure of angle 𝐵𝑂𝐶?
Let’s start by filling in this
angle information onto the diagram, that angle 𝐴𝑂𝐵 is 75 degrees. We need to find out the measure of
angle 𝐵𝑂𝐶. We can work this out once we
realize that this angle at 𝐴𝑂𝐶 is given as a right angle of 90 degrees. So our two angles 𝐴𝑂𝐵 and 𝐵𝑂𝐶
must add to give us 90 degrees. We could in fact say that these two
angles are complementary. The size of angle 𝐵𝑂𝐶 could be
calculated by working out 90 degrees subtract 75 degrees. And therefore, we can give our
answer that the measure of angle 𝐵𝑂𝐶 is 15 degrees.