Cul de Sac by Richard Thompson for November 20, 2017

touché, Peter Otterloop, Jr.

A rhomboid is a type of parallelogram.

I thought a rhomboid was a muscle..?

Alice saves her dad.

From the info I’m gathering, a parallelogram and rhomboid are the same thing. A rhomBUS is different. A rhomboid is two sets of parallel lines but not all four sides have to be equal. Just the opposing lines. But that the same for a parallelogram. For a rhombus, all four sides are equal in length. I remember learning in eighth grade about the definitions of a trapezoid (a figure with at least one set of parallel lines), a parallelogram with two sets of parallel lines (making it also a trapazoid since it does fit the description), a rhombus (a figure with two sets of parallel lines all of equal length, making it also a trapezoid and a parallelogram), a rectangle (a figure with two sets of parallel lines and the opposing lines are equal in length forming four right angles, making it also a trapezoid, a parallelogram). Finally, a square is really special. It’s definition is a figure of two pairs of parallel lines, all of equal length, forming four right angles. This definition includes the definitions of all the others. A square is a trapezoid because it has AT LEAST one set of parallel lines. It’s a parallelogram because it has two sets of parallel lines and opposing sides are equal. It’s a rhombus because the four sides are equal in length and parallel to each other. And it’s a rectangle because the sides form four right angles and opposite parallel sides are equal in length! I love squares!

Picky but….what’s with the weird capitalization today? Why is it “Leaf Collection”, “Nature and Shapes and Colors” and “Shapes and Colors”?

Laugh while you may, Petey. Gotta sympathize with Peter, ‘cause a lot of stuff I once knew (and knew well!) I have forgotten over the decades. It happens, especially when you don’t use the stuff again, ever.

So, I have mixed feelings about Alice’s final outburst….

Kids always try to take their parents down a peg or two. I used to do it, but I have been embarrassed about it for decades. Still, it’s just a rite of kidhood.

All rhomboids are parallelograms, but not all parallelograms are rhomboids.

Rhomboids are those parallelograms whose sides are unequal. The others are rhombuses.

Rhomboids are parallelograms whose opposite sides and angles, and ONLY the opposite sides and angles, are equal. They cannot, therefore, be rhombuses (all sides are equal), nor can they be rectangles (all angles are equal).