A plane through the center of the sphere intersects the sphere in a circle called a ________.?
367920
It's called a Great Circle
715132
Two dimensional. It's a cross-section of a cone (a conic section - look up Euclid).\n\nAn ellipsoid is a three dimensional solid that has three perpendicular cross-sections that are ellipses. Many other 3D shapes have elliptical cross-sections - a prolate or oblate spheroid is pretty much spherical except one cross section is elliptical (the earth is an oblate spheroid, a rugby ball or american football is prolate).
641595
The term is oblate spheroid I believe. Get that extra credit!
766220
If its distance from the center is less than the radius, it's inside.\n\nYou can find the distance from the center using your handy pythagorean theorem.
378956
Of course. Consider a single hill shaped almost spherically. This is the upper hemisphere of a sphere, so the surface area, given some radius r, will be half the surface area of the entire sphere, which is (1/2)*(4*Pi*r^2) = 2*Pi*r^2. \nThe projection of the sphere onto the plane is a disk, with area Pi*r^2, less than the surface area if the flat ground was instead covered by a spherical hill.
524608
Imagine the square of string:\n\nWhat will you do to make it a circle? You would have to bend the sides to form an arc like the way you would bend an archer's bow. For it to become a circle, you have to bend the four sides equally so that the corners will no longer be present.\n\nSo your new circle now will have an area bigger than the square. If you overlap the 2 figures together, you would have a big circle and inside it is a square whose 4 corners touch 4 equidistant points on the circle.\n\nArea of the circle: 64/pi OR 20.3718
428288
A segment with endpoints on a circle is called a chord.\n\nFor example, A diameter of a circle is a segment that has endpoints on the circle and also goes through the center of the circle.  A diameter is the longest chord of a circle.\n\nBut, a circle can have shorter chords than the diameter.  The chord divides the circle into two arcs.  If the chord is a diameter, the two arcs are equal.  If the chord is not a diameter, then the two arcs are not equal.  The shorter arc is called the minor arc and the longer one is the major arc.
638243
1) think of  a series of disks stacked on top of eachother, so thier centers are aligned.  Each disk has a slightly smaller radius then the one under it.  If the disks are very thin (infinately so), and you stack enough of them so that the top disk has a radius of zero (a point), then you have a  cone. \n\n2) Take a circle, and remove some portion of it- like a pizza with one or more pieces removed. Take the remaining portion of the circle, and roll it, so that the straight edges adjoining the removed section are connected together along their entire lengths, and you have a cone.
414316
Hi,\nThe answer is C.\n\nYou could make a ray-diagram and see for yourself...
790971
A circumcenter is the center of a circumscribed circle, which is a circle that contains a polygon inside.  The vertices of the polygon are all on the circle.  The circumcenter is the center of this circle.\n\nAn orthocenter is the intersection point of the 3 altitudes of a triangle.  To draw an altitude, you draw a line from one vertex perpendicular to the base on the other side.  These altitudes intersect @ one point, the orthocenter.\n\n-----------\n\nHope this helps
385894
thats a circle not a sphere.\nYou can't make a sphere out of paper because its too curved.\n\nSee this link it gives you a good explanation why its so hard and some addition links to how to consruct a sphere in other ways
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Almost a coicle!\nEach side would subtend an anhle of slightly more than 1.5degrees so it is very close to a circle. I don't think it has any official name.
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two circles, in parallel planes with the line connecting their centers forming right-angles with each plane in all directions. ... and the walls comprising the set of line segments one of whose end points is on one circel and the other end point on the other circle withe the property that the segments at each point on circle(A) is the minimum distance to circle(B).\n\n.. or, since you use the word "cylinder" in the question:\n\na cylinder, each of whose end-faces is a circle.
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Pi * r^2\n\n(Pi R Squared)\n\nwhere R is the radius (which is also equivalent to half the diameter)
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A sphere.  It has an inside and an outside.
745228
The first thing to do is to extract from this problem a list of the \n"givens" (the things you are told are true). \nSo here's what we are given:\n\nGIVEN - Segment AB is the diameter of a circle with center O\n          Line AC is tangent to circle O at A\n          Line BD is tangent to O at B\n\nTO PROVE - AC and BD are parallel\n\nSTATEMENTS                                     REASONS\n\n1.  Segment AB is a diamter of circle O        Given\n2.  Line AC is tangent to O at A                     Given\n3.  Line BD is tangent to O at B                    Given\n\n4.  AC is perpendicular to AB                  Tangent line is perpen-\n                                                                 dicular to the radius\n\n5.  BD is perpendicular TO BA                  Theorem as stated in \n                                                                  #4 (Theorem 9-1 - If a\n                                                                   line is tangent to a\n                                                                  circle, then the line \n                                                                   is perpendicular to \n                                                                   the radius drawn to\n                                                                  the point of tangency)\n\n6.  AC is perpendicular to AB                  Two lines perpendicu-\n                                                                 lar to same line are\n                                                                 parallel (Theorem 3-7\n                                                                  In a plane two lines\n                                                                  perpendicular to the \n                                                                   same line are parallel\n\n\n\n\n\nLet me know if you need any more help, I can e-mail you more in-depth info.....\n\n\nHope this helps!!!
510334
x = a*sin(ang)\ny = b*cos(ang)\n\nang goes from 0 to 360 degress, a and b determine how oval it is (if a=b it is a circle)