When rotated a angle of 72°, a regular pentagon coincides with its pre-image.
A polygon is regular when all angles are equal and all sides are equal. So, when a pentagon’s all 5 angles and sides are equal then it’s called as a regular pentagon.
The angel subtended by two consecutive radius of a regular pentagon(i.e the line joining vertices and the center of the pentagon) at the center is 72°.
Due to its symmetry when a regular pentagon is rotated 72° around its center(both clockwise and counter-clockwise), it produces same pentagon as before.
The angle of rotation through which the image of a regular pentagon coincide with its preimage is:
B. 72 degrees
Rotational symmetry is the minimum angle by which a figure is rotated such that it coincides with the original figure.
We know that for any n-regular polygon (i.e. a regular polygon with n number of sides) has a rotational symmetry of:
Here we are asked to find the rotational symmetry in case of pentagon i.e. n=5
The angular symmetry is: