Question

The angle of rotation at which point A′ coincides with point D is_ °.

Answer 1

Answer:

The angle of rotation at which point A′ coincides with point D is 144° counterclockwise or 216° clockwise.

Step-by-step explanation:

The given figure represents a regular pentagon. It means the central angle between two consecutive vertices is

$\frac{360^{\circ} }{5}=72^{\circ}$

The vertex D is 2nd vertex from counterclockwise. So, the counterclockwise angle between A and D is

$72^{\circ}\times 2=144^{\circ}$

The angle of rotation at which point A′ coincides with point D is 144° counterclockwise.

$360^{\circ}-144^{\circ}=216^{\circ}$

The angle of rotation at which point A′ coincides with point D is 216° clockwise.

Answer 2

I think the answer is 144.