Subject: Extra unit
Name: daniel
Who are you: Student

There are two triangles each with a base of 8, a height of 3 and an area of 12 units squared and two trapezoids, each with a one parallel side that is 3 and one that is 5 and a height of making it have an area of 20 units squared.
When arranged in a 8x8 square then the total area is 64 units squared, but when arranged in a 5x13 rectangle the total area is 65 units squared, where did the extra unit come from?

this has been bugging me for a while,

Daniel :)

Hi Daniel,

You're right to be suspicious. When you translate shapes in the plane, area should be preserved.

In the 5x13 rectangle, look at the slopes of the upper edges of the trapezoid and the triangle. What does this tell you about how the shapes are really fitting together?