 Hi and how are you all today? My name is Priyanka. The question says construct an angle of 90 degree at the initial point of a given ray and justify the construction. So let us proceed on with this solution. We need to write down the steps of construction also simultaneously. The first step and the foremost step is to draw a ray like this. A is the initial point of this ray. Now as the question says we need to construct the angle of 90 degree at the initial point of a given ray. So the second step will be taking a center and some radius draw an arc of a circle which intersects ray A B say at point D. So taking some radius and taking the center as A we need to draw an arc like this intersecting A B at point D. Now taking the same radius and taking your center as D draw an arc. Now taking this arc as the center draw another arc. Then taking the same radius and these two arcs as the center draw two arcs intersecting at a point. Now join these two points and this is your required 90 degree angle. So let me write down the steps also. The third step will be taking D as the center and with the same radius as before draw an arc intersecting the previous arc A at point. So here let this point be point E. Now taking E as the center and same radius draw another arc let's say point F. So taking E as the center and with the same radius draw an arc intersecting the previous arc at point F like this. Now taking E and F as the centers draw another arc and let us name it as G. Taking E and F as the centers draw another arc intersecting above the points and then what we did was join E G and extend it. Lastly A B is the required angle of 90 degrees. This is and this is angle G A B. So this is the required construction 90 degrees. So I hope you enjoyed this session and make your construction better. Hope you enjoyed and bye for now.