Problem 1.1: Is the following angle acute, obtuse, or right? [Solution]

Problem 1.2: Is the following angle acute, obtuse, or right? [Solution]

Problem 1.3: Is the following angle acute, obtuse, or right? [Solution]

Problem 1.4: Label the exterior and interior of the following angle. [Solution]

Problem 1.5: What three things must be true of adjacent angles? [Solution]