Finding Angle ABC: Geometric Construction with 100° Angle DBC

Question

Determine the size of angle ABC?

DBC = 100°

00:06 Let's find angle ABC.

00:10 This angle is at point B, between points A and C.

00:15 Using the given data, we can find the size of the angle.

00:20 And that's how we solve this question.

We can see from the diagram that angle DBC equals 100 degrees.

We can also see that the size of angle ABC is shown and equals 40 degrees.

Therefore, the answer is 40.