Question:
Construct an angle of 90° at the initial point of a given ray and justify the construction.
Solution:
- Draw a ray OB.
- Cut an arc from point O of any length (as shown in the fig).
- Cut two arcs Q and R on the previous arc with the same radius. (which are at the angle of 60° and 120°).
- Draw two arcs from points Q and R and their point of intersection is S.
- Join O and S.
Hence, ∠SOP is 90°