why?

[white lichen]

In the book it says C = (a,a)
Why it’s not (a,b) ?

[coral pawn]

Because the x and y coordinates are equal?

[white lichen]

Well I don’t think if I wrote this in the exam the teacher will accept it

[gilded smelt]

as

CY=YZ

lenght of YZ = a

so Cy = a

so absicca of C = a

and ordinate = a

[white lichen]

Ok thx