Which of the following cannot be a cross section or slice of a right circular cone?
Incorrect. A circle results when the cone is sliced parallel to its base. 
Incorrect. An isosceles triangle can result when the cone is sliced perpendicular to its base and along its altitude. 
Correct! A right scalene triangle can be a cross section only if the cone is oblique. 
Incorrect. An ellipse results when the cone is sliced all the way through but not parallel to its base. The cube below will be sliced along the dotted lines.
After the cube is sliced completely from base to base what will be the shape of the resulting slice?
A. Square
Incorrect. If the cut was made along the diagonal of the base the slice would be a square.
B. Rectangle
Correct! Since the slice is not made along the diagonal of the base the slice is a rectangle.
C. Pentagon
Incorrect. If the cut was not perpendicular to a base then the slice could be a pentagon.
D. Triangle
Incorrect. If the cut was not perpendicular to a base then the slice could be a triangle.
The rectangle below is a cross section of a solid figure.
The rectangle could not be a cross section of which of the following objects?
A. Pyramid
Incorrect. A rectangular pyramid sliced parallel to its base would result in a rectangular cross section.
B. Cone
Correct! A slice of a cone cannot have right angles.
C. Cylinder
Incorrect. A cylinder sliced perpendicular to its bases would result in a rectangular slice.
D. Prism
Incorrect. A prism sliced parallel or perpendicular to the bases could result in a rectangular slice or cross section.
A solid object casts a circular shadow on the floor. When it is lit from the front, it casts a square shadow on the wall. The object is most likely a —
A. sphere
Incorrect. The shadows or cross sections of a sphere would both be circles.
B. cylinder
Correct! A cross section of a cone sliced parallel to iits bases is a circle and a rectangle when sliced perpendicular to its bases.
C. cone
Incorrect. The shadows or slices of a cone could be a circle but not a rectangle.
D. pyramid
Incorrect. A pyramid cannot have a circular cross section or slice.