April 15 of the Mystery Year was the birthday of Leonardo da Vinci. The clues in this warm-up involve the golden ratio, area of a circle, missing side of a square when given one of the side lengths, square root, proportional relationships, and divisibility. Math connections are made to da Vinci's "Vitruvian Man." Your Zip download includes printable/digital PDFs:1-page printable Student Puzzle, also prepped for Easel1-page Answer Key with sample solutions1-page version of puzzle with expanding f