Question 1: If one angle on a straight line measures 65°, what is the measure of the adjacent angle?

Answer: 115

Question 2: Calculate the missing angle if two angles on a straight line are 80° and ?.

Answer: 100

Question 3: On a straight line, one angle measures 45°. Another angle adjacent to it is 30°. Find the third angle's measure.

Answer: 105

Question 4: Construct a straight line where one angle is 120°. Calculate the other angles formed.

Answer: 60

Question 5: A straight line has angles of 50° and ? at a point. What is the measure of the missing angle?

Answer: 130

Question 6: In a straight line, two angles are 70° and 110°. Are these angles correctly placed? Explain your answer.

Answer: Yes, they are supplementary angles on a straight line.

Question 7: Find the missing angle if the two angles adjacent on a straight line are 95° and ?.

Answer: 85

Question 8: A straight line forms angles of 40° and 75°. Calculate the third angle.

Answer: 65

Question 9: A straight line has three angles: 55°, ? and 80°. Find the missing angle.

Answer: 45

Question 10: Identify the common mistake in the following reasoning: 'Since angles on a straight line add up to 180°, if one angle is 100°, the other must be 80°.'

Answer: Incorrect because only two angles are considered, but the total on a straight line is 180°, so the other angle should be 80° only if only two angles are present, not necessarily in all cases.

Question 11: A diagram shows a straight line with an angle of 135°. Calculate the adjacent angle.

Answer: 45

Question 12: Challenge: Two angles on a straight line are 2x + 10 and 3x - 20. Find the value of x and the angles.

Answer: x=20, angles=50 and 40