No, it never can be a right triangle.
First, all the angles of an equilateral triangle is 60 degrees because all angles are the same and all the angles add up to 180:
180/3 = 60.
So if it is a right angle it needs one angle 90 degrees which an equilateral triangle can't have,
I think the person on top is right
9t = 27.99
5t = ?
Cross-multiply : 9t? = 139.95t
?=15.55
Each corner angle of a square is 90 degrees.
This means every 90 degree rotation ( Counter clockwise) would move A to the next corner.
Since B is the corner below A, it would take a 90 degree rotation fr A to map on B.
