Question

Help checking my answer to geometry question? Thanks!

Which shape listed below will result from cross section d?

Answer 1

rectangle
decagon
triangle
hexagon
trapezoid
None of the above

Answer 2

I think it is a hexagon but I'm not positive.

Answer 3

a hexagon is polygon with 6 sides

Answer 4

Yes, I know what it is. Is that correct?

Answer 5

This is what a hexagon looks like
https://www.google.com/search?q=paraboloid&biw=1366&bih=653&source=lnms&tbm=isch&sa=X&ei=j0OPVbPUNMTDggTu94CwAQ&sqi=2&ved=0CAYQ_AUoAQ#tbm=isch&q=hexagon

Answer 6

that shape is a parabola

Answer 7

I know what a hexagon is and what it looks like. It is not the shape of a parabola BUT it says with the cross section of d. Sorry, I accidentally put the question as the cross section of c not d. The question is: Which shape listed below will result from cross section d?

Answer 8

You wrongly identified something as a polygon, so I just wanted to make sure. A is a circle, B is an ellipse, C is a parabola, and D is a rectangle. The rectangle is the only polygon in the picture.

Answer 9

Sorry about that. Thank you for explaining. I thought C was a half ellipse. And I don't exactly understand why D is a rectangle. Can you help clarify? Thanks! :)

Answer 10

B is an ellipse and C is is half an ellipse. Isn't it?

Answer 11

@peachpi

Answer 12

D is a rectangle because the cross section is taken perpendicular to the base of the cylinder. C isn't a half ellipse I think because of the distances to the focus. It kind of curves more sharply than an ellipse would

Answer 13

Thank you! So, the cross section is the shape that the section that is cut off looks like? Also, parabola is not an option for c. These are the options they give for C:
half ellipse
trapezoid
isosceles triangle
equilateral triangle
pentagon
None of the above

Answer 14

I personally would go with none of the above. BUT if you guys haven't studied parabolas in class yet they may just be using "half ellipse" as shorthand because that's how they think you'll refer to it, if that makes sense.

Answer 15

basically, if you guys have done parabolas, then you should be able to recognize it, and go with NOTA.
If you haven't done parabolas, you don't know what that is, so go with half ellipse

Answer 16

Okay, thank you! Parabolas were not something that we covered in the section. Also, there is one more question that I have answered but I don't know if I'm right. Can you help? Thanks!

Which solid, no matter at which angle you cut it, will always have a circle for a cross section?

Sphere
Circle
Cylinder
Icosahedron

I am quite sure that it is a sphere, but if I am wrong then it should be a cylinder.

Answer 17

yes it's a sphere.

Answer 18

Thank you so much! You've been very helpful! :)

Answer 19

you're welcome