A circle is 360° all the way around; therefore, if you divide an arc's degree measure by 360°, you find the fraction of the circle's circumference that the arc makes up. Then, if you multiply the length all the way around the circle (the circle's circumference) by that fraction, you get the length along the arc.
The type of transformation that turns a figure without changing the size or the shape of the figure is called a ROTATION. An example is given in the diagram below. The triangle has been rotated 90° about the origin
