Curated OER
How Do You Find a Scale Factor in Similar Figures?
Three angles of one triangle are equal to the corresponding angles in another triangle. Use a ratio of corresponding sides to find the scale factor. Actually, there are two scale factor values. The instructor will explain how to get both...
Curated OER
What are Similar Figures?
Similar figures have the same shape, the same corresponding angles, but different lengths of their corresponding sides. The teacher explains just what all that means. She demonstrates how to compare the two shapes to prove they are similar.
Curated OER
Types of Angles
Acute, obtuse, right, and straight are all different types of angles. This clip provides a brief definition and example of each of the four types of angles. Tip: Have your class go on an angle hunt, the team that finds the most of each...
Khan Academy
MTEL Math Practice Test: 36-40
Sal goes into detail when solving these problems on the practice MTEL math test, especially the complicated details of question 36. Viewers will rest assured of the ease with which Sal addresses these increasingly tricky problems.
Curated OER
How Do You Classify Triangles?
Triangles are classified by their angle measurement as well as by the length of their sides. Here are some names that identify the types of triangles: isosceles, equilateral, scalene, obtuse, and acute. Watch this video to learn about...
Curated OER
What are Equilateral, Isosceles, and Scalene Triangles?
Triangles are classified by their angle measurement as well as by the length of their sides. Here are some names that identify the types of triangles: right, isosceles, equilateral, scalene, obtuse, and acute. Watch this video to learn...
Curated OER
What are Acute, Obtuse, and Right Triangles?
Triangles are classified by their angle measurement as well as by the length of their sides. Here are some names that identify the types of triangles: right, isosceles, equilateral, scalene, obtuse, and acute. Watch this video to learn...
Curated OER
How Do You Find the Sum of the Interior Angles of a Polygon?
Squares, pentagons, triangles, polygons. How is it possible to figure out the sum of the interior angles of any of these multi-faceted shapes? There's got to be a formula. Of course there's a formula. That's what algebra is all about,...
Curated OER
What are Acute, Obtuse, Right, and Straight Angles?
Angles are identified by the measurement of their angles. Well, that would make sense. The instructor illustrates four different angles and their names by identifying their degrees. Zero to less than 90 degrees is an acute angle, while...
Curated OER
What are Supplementary Angles?
What are supplementary angles? They are two angles that when added together make 180 degrees on a straight angle line. Hard to picture that? Then watch this video and see how the instructor illustrates this on a diagram.
Curated OER
What Does Congruent Mean?
Two figures are congruent if they have the same size and shape. Line segments can also be congruent if they are of the same length. Vertical angles created by intersecting lines are always congruent. Polygons that have matching angles...
Curated OER
How Do You Use Supplementary Angles to Find a Missing Angle?
How can a straight line be called a straight angle? Can angles be combined to form a straight angle? Yes, supplementary angles can be combined to make a straight angle and that is how one can find the value of a missing angle. Take a...
Curated OER
How Do You Find a Missing Angle in a Triangle?
The interior angles of any and ALL triangles adds up to 180 degrees. So if given two of the angle degrees, is it possible to find the value of the third angle? Yes! Use the triangle sum theorem to solve for the missing angle. Watch this...
Curated OER
How Do You Find Missing Measurements of Similar Figures Using a Proportion?
Two similar triangles have the same angles, but their legs have different lengths. This means their angles are congruent, and thusly, their corresponding sides are congruent. So there is a missing measurement that needs to be found. Set...
Curated OER
What is a 30¡-60¡-90¡ Triangle?
Is it possible to take an equilateral triangle and cut it in half to make a 30-60-90 special triangle to make it easier to solve a problem? Why yes, of course! It's even possible to find the missing length without using the Pythagorean...