Bluebook SAT Test Lines, Angles, and Triangles 7 — Questions and Answers
Question 1: In a triangle, angle A = 90° and angle B = 38°. What is angle C?
- 38°
- 42°
- 52° (Correct answer)
- 62°
Correct answer: 52°
Angle C = 180° − 90° − 38° = 52°.
Question 2: Which angle pair is always congruent when two parallel lines are cut by a transversal?
- Co-interior angles
- Supplementary angles
- Alternate interior angles (Correct answer)
- Adjacent angles
Correct answer: Alternate interior angles
Alternate interior angles formed by a transversal and parallel lines are always equal.
Question 3: Isosceles triangle RST has RS = RT and vertex angle R = 100°. What is each base angle?
- 40° (Correct answer)
- 50°
- 80°
- 100°
Correct answer: 40°
Each base angle = (180° − 100°) ÷ 2 = 40°.
Question 4: Parallel lines are cut by a transversal. The angle at the top-left is 115°. What is the co-interior angle at the bottom-right?
- 65° (Correct answer)
- 75°
- 115°
- 180°
Correct answer: 65°
Co-interior angles are supplementary: 180° − 115° = 65°.
Question 5: In similar triangles PQR and STU, angle P = 55° and angle Q = 75°. What is angle U?
- 50° (Correct answer)
- 55°
- 75°
- 80°
Correct answer: 50°
Angle R = 180° − 55° − 75° = 50°; U corresponds to R, so angle U = 50°.
Question 6: Lines a and b are parallel. An alternate exterior angle at a measures 62°. What is the alternate exterior angle at b?
- 28°
- 62° (Correct answer)
- 118°
- 152°
Correct answer: 62°
Alternate exterior angles formed by parallel lines are equal: 62°.
Question 7: Two parallel lines are cut by a transversal. Corresponding angles are (7m − 11)° and (4m + 16)°. What is m?
- 7
- 9 (Correct answer)
- 11
- 13
Correct answer: 9
7m − 11 = 4m + 16 → 3m = 27 → m = 9.
Bluebook SAT Test Lines, Angles, and Triangles 7
In a triangle, angle A = 90° and angle B = 38°.
What is angle C?