Being able to compare angles can help us in this lesson. Let's try this problem to review.
Which of these angles is larger?
Let's see how we can use angles we know to estimate other angles.
Which angle is equal to $45$45 degrees?
Estimate the size of the angle made by the mountains at the center.
Less than $45^\circ$45°
Equal to $180^\circ$180°
Greater than $90^\circ$90°
If we remember some important angles, we can use those to estimate other angles.