Trapezoid Margaret M. Housinger Isosceles trapezoids with integral sides in which a circle can be inscribed. The example presented is geometric in nature, it deals with the characterization of a parallelogram. Charalampos Toumasis Investigations of sets of sufficient conditions. Solving the problem of finding all rectangles with integral dimensions whose area and perimeter are numerically equal.
Analytic proofs are also involved.
An activity for demonstrating many geometric relationships from angle sums of polygons to properties of parallelograms. Activities involving standard convex quadrilaterals. Lyle R. Smith Differentiating between area and perimeter for rectangles and between volume and surface area for rectangular solids. Determining the change in area produced by making a change in some property of a particular figure. Median of a Trapezoid Pamela Allison Using the result about the segment joining the midpoints of the sides of a triangle in order to find the length of the median of a trapezoid.