Video of the Day " Isosceles Triangle"

Today we have three videos that cover properties of an isosceles triangle. An isosceles triangle is a triangle with two congruent angles and sides.

Video one answers the vertex angle sample problems

Video two reviews how to find the base length of an isosceles triangle

Video Three gives directions on how to find the side length of an isosceles triangle

For more on isosceles triangles see:
MooMooMath/Isosceles Triangles

Video of the Day " Triangle Inequalities"

 What makes a triangle actually a triangle? The video demonstrates what defines a triangle.

Transcript
Triangle Inequalities
Hi Welcome to MooMooMath. Today we are going to talk about proportions of a triangles or what happens to the sides that create a triangle. So the best method for me to show you how this works is actually have some straws to show you how triangles work. The first straw is 8 inches long, the second straw is 6 inches long, and then I have some 4's and some 2's. I'm going to draw you some different combinations of triangles. I will show you with the straws which make triangles and which do not.  O if I have the side length of 8 and I pair this with a side length of 4 and a side of 6. Those three pieces can create a triangle. So the bottom one what happens if I replace the side of 4 with a side of only two?  Look what is going to happen. Can I create a triangle? Well guess what, it doesn't reach. They actually are the same length because this side is 8 and this side is 2, and this one is 6, and it's not large enough to reach to the end. So an 8, 6, and 2 don't work. So what happens if I try a 6 and two 2's? OK here is a side of 6 and here is a 2 and here is a 2. Notice how they can't reach each other. So what are the rules for creating triangles? So let's look at the rules. The rules say the two shorter sides have to add up to or be greater than the length of the longer side. So in the first one worked. It was 8, 6, and 4. So 6 and 4 was 10 which is greater than the longer side of 8. So here is another example. If you have a side of 2 and a side of 4 they add up to a number greater than the longest side of 5 so it is a triangle. If this side is 8 and this side is 6 the side of 4 that one works. So let's write the inequality that actually goes with that to represent that it works. So we have a side of 4 inches and a smaller side of 6 inches and they add up to a side greater than 6 inches. Yet the side that was 2 and another of 2 does not add up to a number greater than side that was 6 so this one doesn't work. So the 2 small sides have to add up to be equal or greater than the longer side. Hope this was helpful.

For more on triangle inequalities and an infographic please see MooMooMath/Triangle Inequalities

Video of the Day " Similar Triangles"

What are similar triangles? Similar triangles are triangles in which the only difference is size. Similar triangles have corresponding sides that have the same ratio and equal angles.

Video Guide
0:15 Definition Similar Triangles
1:04 Rules for solving similar triangles explained  
       Set up a proportion then solve the proportion
1:37 Sample problem similar triangles solved with step by step directions
2:45 Sample problem finding missing sides on similar triangles with step by step directions

For more information see MooMoo Math Similar Triangles

Video of the Day " How to divide and multiply radicals"

How to divide and multiply radicals

In this video you will .....

Learn how to add radicals

Learn how to multiply radicals

Simplify square roots

Learn how to divide radicals

For six more videos on radicals please see: MooMooMath/Radicals

Video of the Day " Are these lines perpendicular?"

"Are these lines perpendicular?"

Given points how do you determine if the lines created from ordered pairs are penpendicular or not.
Review: Lines are perpendicular if the slopes are negative reciprocals or multiply to -1
Step 1. Use the slope equation to calculate the slope from the ordered pairs.
Step 2. Look at the slope from each line and see if they are a negative reciprocal or if you multiply the two slopes together it equals -1

For more on perpendicular lines see MooMooMath/Perpendicular Lines

Video of the Day " What is a Rhombus?"

What are the properties of a rhombus? A rhombus has four congruent sides, opposite angles that are congruent, and when the diagonals of a rhombus bisect they form four right angles.
MooMooMath/Rhombus

Transcript

What is a Rhombus?

Hi welcome to MooMooMath. Today we are going to look at the properties of a Rhombus. I have drawn a figure that looks like a Rhombus. We have DOGS and a rhombus falls in the quadrilateral family as a parallelogram. So we have quadrilaterals then a smaller sub of parallelograms with rectangles over here and rhombuses over here and these two (rectangles and rhombuses) are not the same. Since a rhombus is a parallelogram it does have all the properties of a parallelogram. So it has opposite sides O and G and D and S that are congruent and they are also parallel and the OG and SD are also parallel. What sets a rhombus apart that not only are the opposite sides congruent (equal) top to bottom, left to right all four are congruent. So this side is 5, this side is 5, all four sides are a 5 so that is why I call it a squished square  So we have opposite sides that are congruent, opposite angles that are congruent, OS and DG are opposite angles. We have parallel sides and we can have the angles being supplementary. D and O are supplementary and O and G are supplementary. Now what sets the rhombus apart besides these four sides being congruent is it has some properties with the diagonals. I will draw OS and DG and one property is that the diagonals are perpendicular. They cross and make four right angles. Now what is going to happen is O to the center C, let’s call that C,and C ( the center) to S, call that S these two segments are congruent and these two segments are congruent ( points to segments D-C and C-G) and you can see you have 4 congruent triangles. So these smaller triangles are reflections and are congruent to each other. Another property is the diagonals bisect each other. Which just means they cut each other in half. So the segments are congruent. Hope this video was helpful

Video of the Day " What is a Perpendicular Line?"

What is a perpendicular line?

Quick overview of a perpendicular line.

Transcript

Perpendicular

Welcome to MooMooMath. Today we are going to look at perpendicular lines. What are perpendicular lines or what is perpendicular? Well perpendicular are two lines that intersect at 90 degree angles. So let’s look at a couple of examples of where we will see those. So we have two lines and they are intersecting at 90 degree angles, and I will label it with a little box that represents 90 degrees, and once we know this is 90 degrees we know the other three are 90 degrees because these are lines and lines have a degree of 180 so that would make all four of these 90 degrees. Now let’s look at the two line segments. This angle is 90 degrees and you will often see this in a right triangle. So a right triangle has two segments that are perpendicular and measure 90 degrees. So that is perpendicular lines. Hope this helps

For more information and examples of perpendicular lines see: MooMooMath/Perpendicular Lines

Video of the Day " Measuring angles with a Protractor"

Protractors are used to measure angles. Today's video gives step by step directions for using a protrator to measure an angle
For more information and a nice applet to practice measuring angles with a protractor see: MooMooMath/Protractor