Corbett Maths
Shortest Distance between Line and Point
A short video shows how to find the shortest distance between a line and a point on the coordinate plane. Using the fact the shortest distance is the perpendicular, the presenter shows the class how to find the intersection of the two...
CK-12 Foundation
Applications of the Pythagorean Theorem: Lesson
The Pythagorean Theorem works for something other than right triangles; show your class all it can do. Using information from the Pythagorean Theorem, the video shows how to determine whether a triangle is an acute or obtuse triangle....
Krista King Math
Area of Trapezoids
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...
Krista King Math
Area of a Triangle
Triangles are not all created the same. The instructor shows how to find the area of different types of triangles using the formula. She also includes an example requiring coordinate geometry.
Krista King Math
Area of Parallelograms
Ensure a solid understanding of the components of a parallelogram. The instructor highlights the key concepts when determining the area of a parallelogram. He presents the formula used for parallelograms as images and as...
Brightstorm
Area of Parallelograms
Make math easier by showing the class that even formulas can be parallel — just explore the area of a parallelogram. Learners discover how to create a rectangle from a parallelogram, then make the connection that the...
Krista King Math
Distance Between Two Points
How does the Pythagorean Theorem become the distance formula? The video instructor begins by explaining the application of the distance formula. She then shows graphically how the distance formula is just an extension of the Pythagorean...
Khan Academy
Khan Academy: Geometry: Inradius Perimeter and Area
Proof that the area of a triangle is equal to half the inradius times the perimeter of the triangle, or the area is equal to the inradius times the semiperimeter. This video also appears in the Geometry: Circles strand. [7:29]
Khan Academy
Khan Academy: Geometry: Finding Area Using Similarity and Congruence
Explains how to determine the area of a pentagonal shaded region in a triangle. The triangle that is broken into multiple similar and congruent triangles. [10:07]
Khan Academy
Khan Academy: Geometry: Ca Geometry: Pythagorean Theorem, Area
Demonstrates solutions to problems #36-40 of California Geometry released state test questions. Problems address understanding of area and knowledge of the area formulas for trapezoids, squares, parallelograms, and triangles. [10:44]
Khan Academy
Khan Academy: Geometry: Area of a Parallelogram
Demonstrates how to derive the formula for the area of parallelogram based on the area formula for a triangle. [5:42]
Virtual Nerd
Virtual Nerd: Find the Height of a Triangle if You Know the Area and Base
Take a look at this tutorial to learn how to use the formula for the area of a triangle to find the height if you already know the area and the length of the base. [6:09]
Virtual Nerd
Virtual Nerd: What Is the Formula for the Area of a Triangle?
You can find the area of a triangle by using the same formula for the area of a parallelogram. Watch this tutorial to see how it's done. [4:44]
Virtual Nerd
Virtual Nerd: How Do You Find the Area of a Triangle?
If you know the length of the base and the height of a triangle, it's easy to find the area. This tutorial illustrates how to plug the numbers into the formula for the area of a triangle and solve. [3:44]
Khan Academy
Khan Academy: Triangles: Finding Area Using Similarity and Congruence
Explains how to determine the area of a pentagonal shaded region in a triangle. The triangle that is broken into multiple similar and congruent triangles.
Khan Academy
Khan Academy: Geometry: Area, Pythagorean Theorem
This video shows an understanding of the sum of the interior angles of polygons, properties of parallelogram, lateral area of a cone, area of a kite, and circumference of a circle.
Khan Academy
Khan Academy: Triangles: Triangle Area Proofs
A video proving that the area of any triangle is half the product of the base and the height.
Sophia Learning
Sophia: Area of a Parallelogram With Triangles and Rectangles
In this video tutorial lesson, determine the area of a parallelogram using triangles and rectangles then assess learning with a quiz. [3:34]
Sophia Learning
Sophia: Area of a Trapezoid
This video lesson demonstrates how to solve for the area of a trapezoid. The tutorial includes detailed examples. Students can check their understanding with an assessment.
Sophia Learning
Sophia: Area of Regular Polygons
This video lesson demonstrates how to find the area of any regular polygon using the apothem. Students can check their understanding with an assessment.
Mucho Math
Algebra2go: Finding Perimeter of Rectangular Shapes
This video requires students to find missing side lengths of rectangular shapes prior to finding the perimeter.
Art of Problem Solving
Art of Problem Solving: Areas of Rectangles and Right Triangles
Video tutorial introduces the area of a rectangle and discovers a formula for the area of a right triangle. [4:44]
Khan Academy
Khan Academy: Area of Equilateral Triangle (Advanced)
Sal finds a shaded area defined by two equilateral triangles whose side lengths are given.
Khan Academy
Khan Academy: Area of Diagonal Generated Triangles
Watch Sal prove that the areas of the pairs of triangles generated by the diagonals of a rectangle are equal.