A horizontal plane passes through a cone that has a horizontal base.

Which figure or figures can be produced? Select all that apply.
point
triangle
circle
line segment
trapezoid
rectangle

Question

A horizontal plane passes through a cone that has a horizontal base.

Which figure or figures can be produced? Select all that apply.
point
triangle
circle
line segment
trapezoid
rectangle

e.mccormick · Answer

Well, which do you think and why?

anonymous · Answer

circle and line segment?

e.mccormick · Answer

Well, I can understand circle becuase cones have a circular base.  But how would you get a line segment?

anonymous · Answer

nvm i dont know wat i was thinking!!!!!!!

e.mccormick · Answer

The key is that both the base and the plane are horizontal.  That means parallel.  There are two answers to this, and yes, circle is one.

anonymous · Answer

point?

e.mccormick · Answer

Yes.  When just the tip touches.

anonymous · Answer

o i get thank u so its point and circle?

e.mccormick · Answer

Yes.  If it was a perpendicular or vertical and horizontal situation it would be different.  That has three possible answers.  And at some other random angle is 4 or 5 depending on if it is 1 cone or an hourglass.

anonymous · Answer

o i get t thank u so much!!! can u help on another?

e.mccormick · Answer

Sure.

anonymous · Answer

attachment

anonymous · Answer

wrong one!!!!!!

anonymous · Answer

attachment

anonymous · Answer

A right triangle is rotated around a line that includes one of the legs of the triangle.

What figure is created?

a pyramid
a cone
a larger triangle
a diamond
two cones sharing a base

e.mccormick · Answer

OK.  It is a shape from the roatation.  So that is a cross section of part of the shape.  

Ever taken something like a jump rope and spun it really fast and it makes sort of a ball shape?  Or spun from just one end it it makes a disk?  They are talking about doing the same sort of thing.

anonymous · Answer

o so would it become a larger triangle?

e.mccormick · Answer

Well, not a flip.  A rotation.  Spinning, so a 3d shape.

e.mccormick · Answer

OOH!  I know a site wth an example pic.

anonymous · Answer

so a diamond?

e.mccormick · Answer

Ignore all the volume and calculus stuff. Just look at the first two images: http://tutorial.math.lamar.edu/Classes/CalcI/VolumeWithCylinder.aspx The one on the left is rotated around the y axis and makes the one on the right.

e.mccormick · Answer

Whenever you have rotation, some sort of circle is involved.  That is the nature of rotating things.

anonymous · Answer

so 2 cones sharing a base?

e.mccormick · Answer

Well, you have one triangle, so I don't see how you would get 2 cones...

anonymous · Answer

i dont see how u would even get one!!! but its either a diamond or pyramid

e.mccormick · Answer

|dw:1403565409631:dw|

anonymous · Answer

oooo wow now i get it!!! u should of done that in the first place so its a cone!!!!!!!!!!!!

e.mccormick · Answer

Yep! I also found a good reference for a few others: http://www.sparknotes.com/testprep/books/sat2/math1c/chapter7section5.rhtml

anonymous · Answer

o ok thank u haha!!!!!!

e.mccormick · Answer

This thing on conics shows some of the intersection things I talked about: http://staff.argyll.epsb.ca/jreed/math30p/conics/sections.htm Ignore the formulas, they are probably a little more than you need yet, and focus on the pictures.

anonymous · Answer

ok!!!! appreciate it

e.mccormick · Answer

np.  have fun!

anonymous · Answer

hahaha ill try!!!!!!