A motivating activity is coupled with the use of algebra to explore the process for identifying the value of an angle. Somehow, it feels like a bit like magic when Sal shows the solution for the final problem. Also, it would be...

Providing an exploration of parallel lines, this resource requires students to not only practice calculations, but also to analyze angles. By asking viewers to decide whether two lines are parallel based upon the information given, this...

While exploring the concept of transversals, Sal discusses corresponding angles, congruent angles, and opposite/vertical angles. He provides a thorough summation of these mathematical concepts. It is the first installment in a series...

Perpendicular lines intersect to form right angles - four of them to be exact. Vertical angles, congruent angles, 90 degrees each, these are some of the special properties of perpendicular lines. Watch this video to find out a couple...

So you have a transversal line intersecting two parallel lines and you are looking for a value that would make two corresponding angles congruent. You have all the information needed to write an equation to find the value. So write that...

Parallel lines with a transversal and one given value, find the value of the other seven angles. There are many geometric terms about angles and lines to know the meaning of and understand their relationship to each other. Understanding...

What makes vertical angles so special? Here's a few words that might help you figure out why: intersecting lines, congruent angles, opposite, supplementary angles. Still wondering? Then watch this video for a good explanation of vertical...

A closed figure with four sides means it's a quadrilateral. Each of the different types of quadrilaterals have special properties. The instructor in this video explains the special properties of a rhombus. Parallel sides and congruent...

What makes a polygon a regular polygon? Does this mean there are irregular polygons? For a polygon to be classified as a regular polygon, all the sides must be congruent and all the angles must be congruent. Those are the two rules that...

A rectangle, a rhombus, a square, a trapezoid - are any of these a parallelogram? What are the criteria that make a shape a parallelogram? It has something to do with parallel sides, congruent sides, and congruent angles. Help your young...

There are two parallel lines intersected by one straight line, what's that one line called? A transversal. There are a few more things to know about transversal lines and the angles they create. What are vertical angles? Are they...

Finding the missing values of two angles in an isosceles triangle is not as difficult as it sounds. But how can two out of three angle's measurements be found? Well, there are special properties about an isosceles triangle which make...

A motivating activity is coupled with the use of algebra to explore the process for identifying the value of an angle. Somehow, it feels like a bit like magic when Sal shows the solution for the final problem. Also, it would be...

Providing an exploration of parallel lines, this resource requires students to not only practice calculations, but also to analyze angles. By asking viewers to decide whether two lines are parallel based upon the information given, this...

While exploring the concept of transversals, Sal discusses corresponding angles, congruent angles, and opposite/vertical angles. He provides a thorough summation of these mathematical concepts. It is the first installment in a series...

So you have a transversal line intersecting two parallel lines and you are looking for a value that would make two corresponding angles congruent. You have all the information needed to write an equation to find the value. So write that...

What makes vertical angles so special? Here's a few words that might help you figure out why: intersecting lines, congruent angles, opposite, supplementary angles. Still wondering? Then watch this video for a good explanation of vertical...

Continuing his SAT review session, Sal explores problems with slopes, linear equations, and congruent angles. He begins problem 10 (geometry) but finishes the problem in the next video.

Learners investigate properties of similar figures. In this properties of similar figures lesson, pupils construct similar figures using Cabri Jr. They dilate their figure to create a similar one, and discuss the relationships between...

With a clean, direct resource like this one, learners can easily focus on the task at hand, which is clearly communicated. They practice figuring the missing measures of vertical angles given the measure of their complement or...

In this geometry activity, students read the definitions of right, acute, and obtuse angles in a box at the top of the page. They label 6 angles and use a protractor to measure 3 pairs of angles. They tell whether the angles are...

In this name the property worksheet, high schoolers solve 10 short answer problems. Students identify the property illustrated by the given statements about congruent angles and segments.

Students use similar triangles to find missing heights.  In this using similar triangles to find missing heights lesson plan, students use proportions to find the heights of missing side lengths.  Students find the height of trees and...

Students explore the concept of angles.  In this angles lesson, students determine the relationships of vertical, complementary, supplementary, and adjacent angles.  Students construct proofs using their Ti-Nspire about vertical angles...