Calculate Angle ABC: Geometry Problem with 70°, 18°, and 20° Angles

Question

What is the size of angle ABC?

00:00 Find angle ABC

00:03 The entire angle equals the sum of its parts

00:07 Let's sum its parts and solve to find the angle

00:10 And this is the solution to the problem

In order to calculate the value of angle ABC, we will begin by calculating the sum of all the given angles.

That is:

$ABC=70+20+18$

$ABC=108$

108