Answer:
Regular polygons have all their angle the same. 90 degree angles can only make a square.
Step-by-step explanation:
To be regular, all angles have to be congruent. That would be 7 right angles The sum of the angles for an n-sided polygon is (n-2)180 or when n=7 that is 5(180) which is 10(90). and you have only 7 times 90 if they were all 90.