- A20°
- B45°
- C75°
- D15°
Step-by-Step Solution
60° cannot be trisected with compass and straightedge, so 20° is not constructible. But 45 (bisect 90), 15 (bisect 30), and 75 (60+15) are all constructible.
Answer: A) 20°
By repeatedly bisecting constructed angles, which of the following can NOT be constructed with only a compass and straightedge?
Class 9Constructions of TrianglesGeometry
Master this chapter in 30 minutes a day.
Don't just memorise the answer — build a daily practice habit.
Practice 5 Similar Questions Free →All Constructions of Triangles practice questions
More Class 9 Constructions of Triangles practice
To construct a triangle when its perimeter and two base angles are given, the first step…An equilateral triangle of side 5 cm is to be constructed. Each interior angle of this…How many distinct (non-congruent) triangles can be constructed when all three sides are…To construct a 120° angle with a compass, how many successive 60° arc steps of equal…Which congruence condition guarantees a unique triangle when two sides and the angle…