Friday Fave for November 3

Do you know what the Friday Fave wishes there were more of in the world?


Isosceles trapezoids, to be specific.

Build the Arch—this week’s Friday Fave—has you building arches from isosceles trapezoids. Perhaps you’ll use just a few isosceles trapezoids; perhaps you’ll use many.


You’ll definitely be thinking about relationships in the trapezoid’s angles, and probably you’ll be noticing a relationship between the cut angle and the number of trapezoids you’ll need to build the arch.

In any case, your goal is to describe a good cut angle with algebraic formality. The experimentation and analysis you do up front is going to be the proverbial keystone in your process.

Isosceles trapezoids, angle relationships, algebraic symbols, and a chance to be the stone mason; these all add up to this week’s Friday Fave.

While you’re thinking about trapezoids and angles, the Friday Fave recommends these additional activities.

Polygraph: Shape Bucket

Polygraph: Advanced Quadrilaterals

Lines, Transversals, and Angles