Answer:
#17 Complementary 
#18 Neither 
Explanation:
Complementary Angle: If sum of two angles is right angle then both angles are complementary to each other. 
Supplementary Angle: If sum of two angles is straight angle then both angles are supplementary to each other.
#17 In figure 1
∠1 + ∠2 = 90°
Sum of ∠1 and ∠2 is 90° which is right angle. 
Therefore, ∠1 and ∠2 are complementary angles. 
#18 In figure 1
Sum of ∠1 and ∠2 neither 90° not 180° 
Therefore, ∠1 and ∠2 neither complementary angles nor supplementary angles.