You are given a rectangular piece of paper that has length x=31.2 cm and height y=24 cm. the lower right corner is to be folded to the top edge forming a triangle as shown. determine the maximum and minimum area of a triangle that can be constructed.

At first, we can draw a rectangle with length equals to 31.2cm and height is 24 cm. Then, we when we hold the rightmost bottom corner, moving it until to the top of the rectangle, we can attain a right triangle of which the height is still the same which is 24 cm and new width measurement was changed from 31.2 to 24 cm.  Then the right triangle is now having a base equivalent to 24 and a height which is also equivalent to 24cm. The solution is shown below:
Triangle =1/2 * 24cm * 24cm
Triangle = 288 cm²

This is the maximum triangle that can be constructed.