Area and Perimeter Formulas Students match the formulas of basic polygons and circle with the name or picture of the geometric shape. Tools A B Area of triangle bh/2 Area of Circle pi(r^2) Circumference of Circle pi (d) Perimeter of Square 4s Area of Square s^2 Perimeter of triangle a+b+c Area of Rectangle lw Perimeter of a Rectangle 2 (l+w) Area of Parallelogram bh Area of a Trapezoid 1/2h(b1 + b2)