Additive Angles & Unknown Angles

How the lesson starts: Additive Angles & Unknown Angles

Chef Tomi's pizza puzzle
Chef Tomi cuts pizza into slices with pointy angles. One slice opens 35°. The slice next to it opens 50°. How big is the angle they make together? Let's find out!
Parts add to the whole
When a ray splits an angle, the parts add up to the whole. The first slice opens 35°. The second slice opens 50°. Put them together: 35 + 50 = 85. The whole angle is 85°!
A square-corner slice
A square corner is 90°. Chef Tomi cuts it into a 28° slice and a mystery slice, x. The parts must add to 90. So x = 90 − 28 = 62. Check: 28 + 62 = 90. The mystery slice is 62°!