Area of a Parallelogram - Geometry Help

What is an annulus? Pupils first learn about how to create an annulus, then consider how to find the area of such shapes. They then complete a problem set on arc length and areas of sectors.

In this area and coordinate geometry worksheet, students observe polygons drawn on a coordinate plane. From the model presented, students determine the area of the given figure. This one-page worksheet contains ten problems.

Take young mathematicians on an exploration of the world of 3-D geometry with this seven-lesson unit. After first defining the terms perimeter, area, and volume and how they apply to the real world, students continue on to learn the...

Use patterns to your advantage! The Pythagorean Theorem allows learners to find missing sides of right triangles. Problems include those with both rational and irrational lengths. 

Sliding over a corner makes a rectangle. The resource demonstrates why the formula of the area of a parallelogram works. As part of a larger playlist on basic geometry, the video works examples dealing with parallelogram areas.

Introducing the Heronês formula is the main objective of this lecture. Essentially, it describes how to solve a problem. Heron's formula is given, and then a problem is solved. Since the actual explanation of the formula will be given...

This video is the first installment in a series devoted to exploring Heron's Formula. It is a high-level experience that delves into proof using algebra. It demonstrates a step-by-step process for finding the area of a triangle using...

Go from a parallelogram to a triangle. A segment of an extensive playlist on basic geometry shows the derivation of the formula for the area of a triangle. The resource works examples that require finding a missing side or height to...

Is it right to use the converse? A segment of a basic geometry playlist introduces the Pythagorean Theorem and its converse. The video uses Pythagorean triples when finding whether a triangle is a right triangle or not.

How on earth is one to find the area of a rectangle when he doesn't know the width? Using the diagonal of the rectangle, the length, and the Pythagorean Theorem the missing side is determined and the area is discovered. This clip is...