How to Calculate the Area of a Square from Sides, Perimeters, and Diagonals

The Organic Chemistry Tutor

This instructional math video provides a comprehensive guide to calculating the area of a square using various given parameters. The narrator moves beyond basic side-length calculations to explore more complex scenarios that students encounter in algebra and geometry courses. The video demonstrates four specific problem types: finding area given a numerical side length, finding area given a binomial side length (requiring polynomial expansion), finding area given the perimeter, and finding area given the length of the diagonal. The content bridges the gap between arithmetic geometry and algebraic geometry. Key themes include the application of the standard area formula ($A = s^2$), expanding binomials using the FOIL method, solving for variables using linear equations ($P = 4s$), and applying the Pythagorean theorem ($a^2 + b^2 = c^2$) to derive side lengths from diagonals. The video emphasizes that area calculation often requires intermediate steps to determine the side length first. For educators, this video is an excellent resource for showing how geometry concepts connect with algebra. It is particularly useful for demonstrating why algebra skills are needed in geometric contexts. Teachers can use the specific segments to differentiate instruction—using the first segment for review, the second for connecting polynomials to geometry, and the final segment for advanced applications involving the Pythagorean theorem. The step-by-step narration allows for easy pausing and student prediction during class.