standard_description: Give an informal argument using Cavalieri’s principle for the formulas for the volume of a sphere and other solid figures.
problem_activity: Task
Decide whether each of these statements is always, sometimes, or never true.  If it is sometimes true, draw and describe a figure for which the statement is true and another figure for which the statement is not true.
A rhombus is a square
A triangle is a parallelogram
A square is a parallelogram
A square is a rhombus
A parallelogram is a rectangle
A trapezoid is a quadrilateral


aligns: no