How to Solve for the Height When an Angle & the Length Is Known

[carlospina]

This video is the perfect example of why removing dislikes is wrong.

[whitelung]

I laughed so hard when he pointed to the hypotenuse and called it the adjacent

[AdityaSharma-muhp]

For those who did not get it:
First take out the measure of third angle which is 30 degrees (since sum of all angles = 180 SO, 180-(90+60)=180-150=30)
From reference angle (the 60 degree angle),
Hyp=5
Let Adg=a
Opp=b

Therefore,
Sin(60)=b/5 [Since opp/hyp=sin]
=>5 x Sin(60)=b/5 x 5 [multiply both sides by 5]
=>5 x Sin(60)=b [5 and 5 cancel out]
Hence, using calculator we see length of b=4.33 (approx) units

Now, we can use Sin again(taking refrence angle as 30 degrees)

So, Sin(30)=a/5 [Since opp/hyp=sin]
=> 5 x Sin(30)=a/5 x 5 [multiply both sides by 5]
=> 5 x Sin(30)=a [5 and 5 cancel out]
So, after calculating, we see length of a side is 2.5 units

[computersmith]

S. O. H. C. A. H. T. O. A "Some old hippy caught another hippy to offer advice"

[crumpit]

hypotenuse is where the 5 is. H is the opposite side and the bottom line is the adjacent side.

[cringe]

i was confused to why it is cosine and not sine until i checked the comments lol

[memperkasaya]

imagine using cosine when you actually had to use sine

[andrewg]

Can we PLEASE fix this video? How many kids learning maths have gone to YouTube to find out if they've got the solution or the concept right and are seeing this WHICH IS WRONG?

[christianvelazquez]

Isn’t cosine adjacent/hypotenuse the thing on the board shows sine which is opposite/hypotenuse

[syncnova]

Couldnt be more wrong. its actually sin(60) * 5 or cos(90-60)*5. Omg dude. your a teacher. Get it right.

[cringe]

you didn't explain why h is equal to 2.5

5 = 2h
5/2 = 2/2h (2/2 cancel out)
2.5 = h or
h = 2.5

[imdito]

Take this video down, why are my flat earth videos taken down, but this “math” teacher is still up.

[ethanharrell]

Cosine is adjacent over hypotenuse and the adjacent of 60 is not given and the hypotenuse is 5

[jorkendavsam]

This video is exactly why YouTube needed to keep the dislike button smh

[born_to_be_bored]

This video DID NOT HELP! I got so confused when he pointed at the hypotenuse and said “adjacent”. Like I wasted half an hour doing it WRONG! TAKE THIS GARBAGE DOWN!

[jonathanchang]

Ok, is this wrong?, cuz isn't hypotenuse the longest one?

[alimon]

Cosine is adjacent to the reverse hypotenuse = 0

[huzaifaali]

we apply any trignometry function in place of cos

[johnkeneth]

but if to use sine the answer would be a negative, will be that ok?

[electronG]

This math is incorrect. You meant to use sine not cosine. The video should be fixed or taken down.