Question

Sam, a self-confessed math geek, is mowing his four-sided yard. He is really bored so he tries to remember all of its dimensions. He remembers that one corner is 85°, another is 70°, and another is 105°, but he can’t recall the 4th, so he has to calculate it. Figure out the measure of the fourth corner with him.

Answer 1

100°

Explanation:

Since you want to form a 4-sided figure, the sum of all the vertex angles must be 360°.

Therefore, we can calculate the 4th vertex, like this:

So the measure of the fourth corner is 100°