In algebra tiles, which shapes represent variables?

• A. Squares
• B. Circles
• C. Triangles
• D. Rectangles

Answer: (D)

In algebra tiles, each shape stands for a different part of an expression. A rectangular tile is used to represent the variable part, like x, because it’s easy to show multiples of the same variable by using several copies of that rectangle (for example, two rectangles for 2x, three for 3x, and so on). Constants are usually shown with a small square, and x^2 or higher-degree terms are represented by other shapes (often a larger square) depending on the set. Circles and triangles aren’t used to represent standard terms in this common kit, so they don’t stand for variables. That’s why the variable is represented by rectangles.