Question

Construct with ruler and compass, angle of 90° measure.

Answer 1

The below given steps will be followed to construct an angle of 90°.

1. Draw a line l and mark a point P on it. Now taking P as centre and with a convenient radius, draw an arc of a circle which intersects line l at Q.
2. Taking Q as centre and with the same radius as before, draw an arc intersecting the previously drawn arc at R. 
3. Taking R as centre and with the same radius as before, draw an arc intersecting the arc at S (see figure).
4. Taking R and S as centre, draw an arc of same radius to intersect each other at T.
5. Join PT, which is the required ray making 90° with line l.