8
An octagon may have 1, 2, 4 or 8 angles of rotation.
Four of them because 4*90 = 360 degrees which is a full revolution
4 right angles, no other angles.
A Pentadecagon had 15 sides
A full rotation = 360°; a right angle = 90° → there are 360° ÷ 90° = 4 right angles in a full turn.
1 complete rotation = 360o 1 right angle = 90o 360o ÷ 90o = 4 There are 4 right angles in 1 complete rotation.
4
Four.
8
An octagon may have 1, 2, 4 or 8 angles of rotation.
There are 4 right angles of 90 degrees in a full turn of 360 degrees.
Four of them because 4*90 = 360 degrees which is a full revolution
4 right angles, no other angles.
A Pentadecagon had 15 sides
There are 360 degrees in a full rotation.
Four times - each at 90 degree angles.