Area of the triangle with the given vertices (KristaKingMath)

Learn how to find the area of a triangle with the given vertices. Once you find the equations of the sides of the triangle, this is essentially an area between curves problem.

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Hi, I’m Krista! I make math courses to keep you from banging your head against the wall. ;)

Math class was always so frustrating for me. I’d go to a class, spend hours on homework, and three days later have an “Ah-ha!” moment about how the problems worked that could have slashed my homework time in half. I’d think, “WHY didn’t my teacher just tell me this in the first place?!”

[kristakingmath]

Glad you liked it! Thanks for the comment. :)

[DOLrd]

This is definitely the best explained video on this type of problem. Thank you! I was stuck for a bit.

[autumntaco]

Eight years later and this is still helping people. Stewart's online help videos that come with the online homework are garbage, I went from being confused for 45 minutes to understanding 6 minutes into your video. Thank you.

[kristakingmath]

you certainly don't have to for this particular problem, but using integrals to find the area of shapes like this can be really helpful when the shape is more complex (like a polygon). so it's a good skill to have! :D

[kristakingmath]

i've organized my channel into playlists so you can go in order. check out the "featured playlists" section in the sidebar of my channel page, and start with limits & continuity. that should help get you going in the right direction! :)

[kristakingmath]

hey elizabeth! just plot those other three points, and you'll be able to see the fourth one emerge easily. hint, it's (-4, -2). :)

[laddermonkey]

This video is awesome. The solving process was very well explained. Thank you and keep up the good work!

[wr]

Oh my goodness, thak you so much, I was struggling trying to find an explanation to this exact topic, for my calc II course. You have truly saved my day, again thank you

[truerthanyouknow]

I'm revisiting this after 11 years since being in a classroom and I understood your example. A heartfelt thanks from some guy in Canada :-)

[kristakingmath]

i'm only a teacher on YouTube, but that makes me feel like a teacher!! :)

[yazeedadslgate]

I find you very useful for me !! every time that i have problem i  always come back to your youtube chancel keep up the good work :)

[nathancc]

Who's here rn alot changed u uploaded this vid when i was 5 yr old lol😂😂

[guitarttimman]

Yep. Just did it. Put 3i + j + 0k and -2i +j+0k in a determinant, use Cramer's rule. You get 5k. Take the magnitude of it you get 5. 5 is the area of the completed parallelogram. Now take half of that to get the area of the triangle. BINGO! You get 5/2.

[neettim]

can you do an example where part of graph of the triangle is below the x-axis? How would that be computed? 

[jaysonnelson]

Krista King and friends: How do you know where to draw the dividing line for more complex shapes.

[ThePinoyMamba]

Well done. Super Clear. Love it. Thanks!

[mothersblessingacademy]

you are just doing the questions we need and your explanation is sooo 😉😉😉😃😘😘

[elizabethvasquez]

the coordinates of three vertices (corner pionts) of a rectangle are( -4, 3) (5, 3) and (5, -2)
Plot the fourth vertex of the rectangle on the Coordinate plane grid.

Help ... put more out there thanks, is there an easy way?

[gdogvibes]

or you could just use the area of a triangle
bh(1/2) and add the two triangels

smaller triangle area=1
bigger triangle area =1.5
1+1.5
=2.5
=5/2.
Done. :3

[ShalongMaa]

an easier way is to look at the length of line x=1 between y=(1/3) x and the point (1, 2), which is 5/3, then the area = .5 * (5/3) * 3