Answer:
884. D
885. C ( changed my answer)
886. B
887.A
For number 844, the diameter if the fan is 12 inches. To find Circumference, multiply the radius by two and then pi. The radius of the fan is 6, multiplied by 2 is 12, and multiplied by pi gives 12 times pi.
885 says half of the area gives the circumference. So we can write a formula, (pi*r^2)/2=2*pi*r. If the radius were 4, this would make the equation true. So the answer is 4.
886. Circumference=2*pi*r
r=6.78
2*pi*6.78
13.56*pi
887.
3*3=9
13-3=10
10*23=230
230+9=<u>239</u><u> </u><u>units</u><u> </u><u>squared</u>
Answer:
The problem in the first statement is that it does not say that the lines must be in the same plane.
Suppose in a 3D coordinate axis two lines as:
z = 0, y = 0 (this is the x-axis)
y = 1, x = 0 (this line is parallel to the z-axis but one unit above).
Those two lines are not parallel, and also never meet, so the definition is wrong.
The actual definition should be:
"Parallel lines are two lines that lie on the same plane and never meet"
B: The undefined terms are point, line, plane,...
An example can be "Plane", because if our lines do not lie on the same plane, then we can not use the concept of "parallel lines".
Answer:
-1.
Step-by-step explanation:
1) according to the DeMoivre's theorem:
2) if cos(π)=-1 and sin(π)=0, then cosπ+i*sin(π)=-1.
