Area of Triangles

What Is An Altitude

The definition of altitude is pretty straightforward for most students, so maybe you're thinking this video is too basic. Not true! The most common triangle trick on the SAT and other standardized tests is to make altitudes tricky -- by rotating the triangle and/or making it obtuse -- so this video is worth watching if you ever plan on taking a test that involves triangles!

The Triangle Area Video That Will Save You

Yes, this is the most important triangle video you will ever watch. No, I won't give it away by telling you this ultra-important trick here, because as simple as the trick is, you won't fully appreciate it unless you see me yell it at you in a video.

Basic Triangle Area Problems

When you first learn how to find the area of a triangle, they just give you triangles and tell you the dimensions and ask for area. This video introduces the A=1/2 x base x height formula, and works a bunch of daigram problems, including a few of the trickier ones that a teacher might pull on you on the test.

Areas of Triangles Using Pythagorean Theorem

Another must-watch video. One of the ways a test or teacher can make triangle problems harder is by not giving you all the information you need to plug into the area formula. The Pythagorean Formula is one common way to find missing information, even in triangles that are NOT right triangles.

Areas of Triangles on Coordinate Axes

This is the type of problem every teacher uses where instead of telling you the length of sides of the triangle, they will instead give you the coordinates of the corners of the triangle on the X-Y axes. These can be confusing, but if you use the step-by-step process in this video, you'll be untrickable!

Area of Triangles with Equations of Lines

Yet another very specific type of triangle area problem that you'll probably see. Math teachers love two things -- equations of lines, and trying to make you love equations of lines -- so when they get into the triangles chapter, they love to create triangles made of equations and ask you to find the area!

Areas of Triangles Inside Circles (SAT)

Oh man, if you plan on taking the SAT ever, this is definitely a video you're going to want to watch. Sure, it will help you in geometry class too, especially when you're looking at those crazy circle diagram problems. Circles and triangles: so different, yet they seem to always show up in the same problems.

Areas of Triangles Using SohCahToa

When you're supposed to find the area of a triangle and they give you an angle as well as a side (and you can use calculators), chances are you're supposed to use SohCahToa (trig), even when it's not a right triangle. This video walks you through some common examples, and trick traps to avoid.

Areas of Triangles Using Special Triangles (SAT)

These ones are like the SohCahToa ones, except if you're not allowed to use a calculator, it better be a 30-60-90 or 45-45-90. And there are some triangles that aren't special but you're supposed to realize could be split into special triangles, so this video covers those too. Very important.

Heron's Formula for Triangle Area

Yeah, Heron's Formula. Or as students usually refer to it: "That formula with the big square root and a lot of minus signs that's named after some guy and tells you the area of a triangle?"

Area of SAS Triangles Using Trig

If you've seen this formula in class -- Area = .5(b)(c)(sinA) -- this video is for you. If you haven't seen it in class, it's basically just a plug-and-chug version of using SohCahToa to find area, so maybe you'll like it.

Triangle Area Word Problemse

Yay, word problems! This batch all involve triangles, with a couple practical ones and a couple conceptual ones.