This set of three oversized acrylic blocks is designed for light and prism demonstrations in physics classrooms. The set includes a rectangle measuring 7.5" x 4.3", an equilateral triangle with 7.5" sides, and a right isosceles triangle measuring 7.25" x 5.1". All three blocks are 0.91" (23 mm) thick. The larger-than-standard dimensions improve visibility during whole-class demonstrations, allowing students to observe refraction, reflection, and total internal reflection phenomena from across the room. The optically clear acrylic material provides well-defined light paths through each geometric shape.