Answer:
1. Linear pair
2. Adjacent
3. Complementary
4. Adjacent
Explanation:
Problem 1:
Angles a and b are on a straight line. Therefore, the relationship between them can be referred a LINEAR PAIR.
Problem 2:
Angles a and b share the a common vertex and same side. Therefore, both angles can be side to be ADJACENT to each other.
Problem 3:
Angle a + angle b = 90°
Therefore, they are COMPLEMENTARY angles.
Problem 4:
angles a and b share the same side and a common vertex. They are ADJACENT angles.