You can rotate it through any angle of your choosing.
A square.
You don't rotate the angle, you rotate an object by that angle, for example if you had to rotate something 180o it would flip over.
It is 1 degree after a right angle. A right angle is 90 degrees so the smallest obtuse angle is 91 degrees.
60 degrees, for an equilateral triangle, is the smallest interior angle.
40
None. You can rotate a circle by the smallest possible angle that you can think of and it will be an angle of symmetry. And then you can halve that angle of rotation and still have rotational symmetry. And you can halve that angle ...
60 degrees. You find this by taking 360 and dividing by the total sides (6) which leaves you with the degrees of the exterior angles, this exterior angle is how little you can rotate any polygon for that matter.
A square.
the line of symmetry from the middle
You don't rotate the angle, you rotate an object by that angle, for example if you had to rotate something 180o it would flip over.
If you can rotate (or turn) a figure around a center point by fewer than 360° and the figure appears unchanged, then the figure has rotation symmetry. The point around which you rotate is called the center of rotation, and the smallest angle you need to turn is called the angle of rotation. This figure has rotation symmetry of 72°, and the center of rotation is the center of the figure:
To rotate a mirror so that a reflected ray rotates through 25 degrees, the mirror should be rotated half that angle, which is 12.5 degrees.
In a triangle the smallest angle is always opposite the shortest side. It will always be an acute angle.
54 degrees
It is 1 degree after a right angle. A right angle is 90 degrees so the smallest obtuse angle is 91 degrees.
60 degrees, for an equilateral triangle, is the smallest interior angle.
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