Area and Circumference of a Circle — Formulas and Examples
Learn the area of a circle formula (A = pi r squared) and circumference formula (C = 2 pi r) with clear worked examples and practice problems.
Shapes, area, volume, angles, theorems
Xem tất cả thẻLearn the area of a circle formula (A = pi r squared) and circumference formula (C = 2 pi r) with clear worked examples and practice problems.
Learn how to calculate the area and perimeter of rectangles, triangles, circles, and more with clear formulas, worked examples, and practice problems.
Learn how to find the area of a triangle using the base-times-height formula. Includes worked examples, Heron's formula, and practice problems.
Learn the distance formula with clear derivation, 5 worked examples, and practice problems. Find the distance between any two points on a coordinate plane.
Learn the area of a trapezoid formula with clear explanations, step-by-step examples, and practice problems. Master the parallel-bases method.
Learn how to find the perimeter of rectangles, triangles, regular and irregular polygons with clear formulas, worked examples, and practice problems.
Learn the Pythagorean theorem with clear explanations, a visual proof, worked examples, and practice problems for grades 8-9.
Practice the Pythagorean theorem with 5 worked examples and answers. Find missing sides, verify right triangles, and solve real-world problems step by step.
Solve real-world Pythagorean theorem word problems step by step. Ladders, navigation, construction, and sports — with full worked solutions for grades 8-9.
Learn what Pythagorean triples are, see a list of common triples, and discover how to generate new ones using a simple formula. Worked examples and practice for grades 8-9.
Learn how to calculate the surface area of prisms, cylinders, pyramids, cones, and spheres with clear formulas, worked examples, and practice.