Answer: 10) 615° & -105°
12) -440° & 280°
Explanation:
Coterminal means it is in the exact same spot on the Unit Circle but one or more rotations clockwise or counterclockwise.
Since one rotation = 360°, add or subtract that from the given angle until you get a positive or negative number.
10) 255° + 360° = 615° (this is a POSITIVE coterminal angle to 255°)
255° - 360° = -105° (this is a Negative coterminal angle to 255°)
12) -800° + 360° = -440° (this is a Negative coterminal angle to -800°)
-440° + 360° = -80° (this is a Negative coterminal angle to -800°)
-80° + 360° = 280° (this is a POSITIVE coterminal angle to -800°)