Heron's formula | Perimeter, area, and volume | Geometry | Khan Academy

Using Heron's Formula to determine the area of a triangle while only knowing the lengths of the sides

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[duckface]

for people wondering about the last part where he did 18 and 7 squareroot, you have to find the squareroot of 7 first and multiply that with 18 to get the final answer :)

[gamja_YT]

At the last part where he does the square root of 18 time 9 times 7 times two, instead of the extra step with the 36 you can just multiply 2 and 9 which is also 18, then take out the the 18 and leave the 7 which is a shortcut-ish to getting 18 times the square root of 7.

[yannaaguilar]

It's my exams tomorrow and this is part of it and my teacher did not teach us this so thank you so much !

[nicecoolstuff]

I love Heron's formula! :D

THANKS FOR YOUR KINDNESS
FREE LESSONS ONLINE OF THIS QUALITY ARE VERY RARE!!!
YOU ARE AWESOME MR. SALMAN KHAN!!!!

:D Super excited. :)

[betruetoyou]

I LOVE YOU MAN - YOU'RE A LIFE SAVER

[griftorifto]

OMG I figured this out without the theorem on my own. Well it was off by 0.6~. That must have been down to my calculator rounding it off., then squaring the numbers threw it a little out of proportion. I love Maths! :) Might devise my own formula. If Im right.... BRB

[sat]

Awesome explanation!!!! would you say that the Heron's formula is useful for any triangle problem? except the right triangles, of course?

[alanbajpai]

A= 1/2×b×h= half of isosceles triangle

[cluelessking]

This video was very helpful thanks a lottt!!!!

[waddles]

Anyone else watching this cause they didnt listen in class?

[IraCruzLoveR]

merci .. je comprends heron's formula . . : )

[PaulBatazii-bsxt]

Thank you very much for the video, l was stuck on this question but now it's really simple after watching this video...👍👍👍👍

[icecreamcake]

thank u u just saved my life plz keep up the good work this is so helpful

[hightied]

Thanks for the Video, and what program are you using?

[srushtishetye]

it helped me a lot thank u soooo much😊😊

[betruetoyou]

i love you me salman khan I LOVE YOU I LOVE YOU I LOVE YOU ! these videos are saving my life - if i get to uni it would be thanks to you

[fire]

I'm surprised this isn't taught in schools

[CarlosLopez-tyql]

does the final answer have to be in square root or can you turn it into a whole number?

[YP]

great, now i know how to do my homework.

[isaac]

Why the hell isn't this in my textbook?!