Circles, cylinders, cones, and spheres

Basic geometry and measurement - Radius, Diameter, Circumference & Pi Explained

Learn about circle measurements: radius, diameter, circumference, and pi. Understand how these relate and calculate circumference using the formula C = 2πr.

Basic geometry and measurement - Finding Radius from Circumference

Learn how to find the radius of a circle when given its circumference using the formula r = C/(2π), with step-by-step examples and practical applications.

Basic geometry and measurement - Area of a Circle

Learn how to calculate the area of a circle using the formula A = πr². Includes examples with radius and diameter, plus tips for solving circle area problems.

Basic geometry and measurement - Solving Circle Area Problems

Learn how to find the area of a circle using diameter or circumference. Covers formulas, common mistakes, and step-by-step examples with radius calculations.

Basic geometry and measurement - Arc Length and Area of Partial Circles

Learn how to calculate arc length and area of partial circles by finding the angle fraction and multiplying by full circle formulas, with a step-by-step example.

Basic geometry and measurement - Volume of a Cylinder

Learn how to calculate the volume of a cylinder using the formula V = πr²h, with a step-by-step example showing how base area times height gives you volume.

Basic geometry and measurement - Volume of Cones and Spheres

Learn how cone and sphere volumes relate to cylinders. A cone holds 1/3, a sphere 2/3, and a cylinder 3/3 of the volume with the same dimensions.

Basic geometry and measurement - Solving Cylinder Volume Problems

Learn how to calculate the volume of a cylinder using the formula V = πr²h. Includes a worked example and common mistakes to avoid.

Basic geometry and measurement - Solving Cone and Sphere Volume Problems

Learn to calculate cone and sphere volumes using formulas. Covers an ice cream cone example with radius/height and a sphere using diameter conversion.