The decagon can be divided in 10 equal parts, so if a full rotation is of 360º, a one tenth rotations will be of 360º/10= 36º
So if you rotate the decagon by a multiple of 36º the rotation will be onto itself, i.e. the figure will look as if it wasn't moved.
From the choices given, the angle that will rotate the angle counterclockwise onto himself will be multiple of 36º, the only one is 72º
This figure has 5 lines of symmetry that cross each vertex and 5 lines of symmetry that cross form the midpoint of one side to the midpoint of the oposite side. This is a total of 10 lines of symetry.
So you can reflect the decagon 10 different ways.
The correct choice is C: 36º, 72º, 10, 5
First, you can factor them into (x-8)(x+9)=0 then set x-8=0 and x+9=0, in which you get X = 8 or X = -9
Answer:
Step-by-step explanation:
The answer is c.
The grade of her sci test was 61. First I add 37 to 85, the sum being 122. Then if you divide it in half, you get the quotien and final answer of 61
