Aregular decagon is mapped onto itsslf everytime it is rotated by how many degrees

36° is correct.

Step-by-step explanation:

The degree of rotational symmetry is equal to 360° divided by the number of sides of a regular polygon

360° ÷ 10 = 36°

A regular decagon is mapped onto itself every time it is rotated by 36°

Step-by-step explanation:

A regular decagon means a polygon with 10 sides and all sides are equal.

Refer the given figure, if we rotate by 36° we will get same decagon.

So a regular decagon is mapped onto itself every time it is rotated by 36°

all but the second one

step-by-step explanation:

cuz that one goes over 180

mark brainliest

c.

step-by-step explanation:

she should of added 9^2 and 12^2. that is because it is a^2+b^2=c^2. c^2 is the hypotenuse and should always be bigger than the other two numbers. which is why she should of added 9 squared and 12 squared together instead of 15 squared.