Find the angle of the rotations for the graphs below. The center of rotation is the origin, and the darker image is the preimage. Your answer will be 90°, 270 degrees, or 180 degrees.

  a. 90°

  b. 180°

  c. 180°

Step-by-step explanation:

For these problems there is a bit of a shortcut you can take. Each figure is entirely within one quadrant, and the rotation is said to be by 90° (one quadrant), 180° (two quadrants), or 270° (three quadrants) clockwise.

a. The image is in the adjacent clockwise quadrant, so rotation is 90°.

b, c. The image is in the diagonally opposite quadrant, so rotation is 180°.

0.02

step-by-step explanation:

time of 9 192 631 770 periods of the radiation corresponding to the transition between the 2 hyperfine levels of the ground state of the caesium 133 atom at 0 k (but other seconds are sometimes used in astronomy)

answer: both chords and diameters have two endpoints on a circle. diameters must intersect the center of a circle.