Sophia: Calculating the Area of a Rectangle

Looking at area with a hole. Using algebraic expressions as dimensions, learners see how to calculate the area of a rectangle that contains a square hole. The instructional video shows how to create a single expression for the area of...

Use one-dimensional calculations to make them two-dimensional. An application question provides a perimeter and a relationship between the length and width of a rectangle. The video tutorial demonstrates how to write an equation for...

Around and in—take a different look at rectangles. A portion of a basic geometry playlist discusses the area and perimeters of rectangles. Using the formulas, the presentation works perimeter and area examples with rectangles and squares.

Rectangles, parallelograms, and now trapezoids — so many quadrilaterals! Building on the previous lessons in the series, the video introduces the formula for the area of a trapezoid. The instructor shows images of trapezoids and...

This video lesson demonstrates how to calculate the area of a triangle. It includes detailed examples including ones that use the Pythagorean Theorem. Students can check their understanding with an assessment. [10:43]

Lateral area and surface area are simple concepts, but calculating them is not as easy! Using formulas, learners calculate lateral area and surface area for the same three-dimensional figures. The resource discusses the formula variables...

While the lesson focuses on right triangles, this activity offers a great way to practice the area of all triangles through an interactive webpage. The activity begins with the class taking a square paper and cutting in in half; can they...

Students watch a video lesson that demonstrates how to find the total surface area of a cone. The tutorial includes detailed examples. [2:49]

In this online math instructional activity, students calculate the area of a variety of rectangles given the measure of their vertices. This excellent resource allows the students to check their answers, and to get "hints" should they...

Trying to find the area of a rectangle, a triangle, a circle, or a parallelogram? There are specific formulas to use to calculate the area of these shapes. But the given shape is not any of these. It's a composite shape, which means it...