Question 1: On a straight line, one angle measures 65°. Find the other angle.

Answer: 115

Question 2: Two angles on a straight line are 40° and an unknown angle. Find the missing angle.

Answer: 140

Question 3: If one angle on a straight line is 120°, what is the measure of the adjacent angle?

Answer: 60

Question 4: Calculate the unknown angle if the two angles on a straight line are 75° and x°, and they are supplementary.

Answer: 105

Question 5: A straight line forms an angle of 95°. Find the supplementary angle.

Answer: 85

Question 6: In a diagram, angle A is 50°. The adjacent angle on a straight line is x°. Find x.

Answer: 130

Question 7: Two angles on a straight line are 35° and 100°. Are these angles correctly positioned? Explain your reasoning.

Answer: No, because the angles on a straight line should be supplementary, summing to 180°, but 35° + 100° = 135°.

Question 8: Construct a straight line where one angle is 75°, and find the measure of the adjacent angle.

Answer: 105

Question 9: On a straight line, one angle is twice the other. If the smaller angle is x°, find both angles.

Answer: 60, 120

Question 10: A straight line forms an angle of 150°. Find the measure of the supplementary angle, and verify your answer.

Answer: 30

Question 11: A student incorrectly states that the angles on a straight line can be 100° and 80°. Identify and correct the mistake.

Answer: The mistake is that 100° + 80° = 180°, which is correct, so these can be on a straight line. The mistake would be if they didn't sum to 180°, but as given, this example is correct. Alternatively, if the student's reasoning was that the angles are not supplementary, the correction is that they must sum to 180°.