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Please help :(
A right triangle with area 45 has vertices at (3, 2), (7, 2), and (7, b), where b > 0. What is the value of b?
 one year ago
 one year ago
Please help :( A right triangle with area 45 has vertices at (3, 2), (7, 2), and (7, b), where b > 0. What is the value of b?
 one year ago
 one year ago

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KingGeorgeBest ResponseYou've already chosen the best response.1
If you were to graph this, you could probably see what to do. dw:1338695720852:dwYou want a point on that line so that the area is 45. Can you tell me what the distance is between (3, 2) and (7, 2)?
 one year ago

KingGeorgeBest ResponseYou've already chosen the best response.1
Perfect. Now what's the formula for area of a triangle?
 one year ago

xRAWRRx3Best ResponseYou've already chosen the best response.1
A = 1/2 base times height?
 one year ago

KingGeorgeBest ResponseYou've already chosen the best response.1
Right on. What's the distance between (7, 2) and (7, b) in terms of b?
 one year ago

KingGeorgeBest ResponseYou've already chosen the best response.1
And assuming b is positive.
 one year ago

xRAWRRx3Best ResponseYou've already chosen the best response.1
I'm not sure, that's the part I don't get D: I don't know how to solve it.
 one year ago

KingGeorgeBest ResponseYou've already chosen the best response.1
Well, there's two ways to look at it. The easy way, or the hard way. The hard way uses the distance formula. \[\sqrt{(b2)^2+(77)^2} =\sqrt{(b2)^2}=b2\]
 one year ago

xRAWRRx3Best ResponseYou've already chosen the best response.1
yeah, that's what I tried to do.
 one year ago

KingGeorgeBest ResponseYou've already chosen the best response.1
The easy way is to look at the graph. It's a straight vertical line from (7, 2) to (7, b), so the distance is just \(b2\). Once again, assuming b is greater than 2.
 one year ago

KingGeorgeBest ResponseYou've already chosen the best response.1
One last thing. What's the base and the height of the triangle?
 one year ago

xRAWRRx3Best ResponseYou've already chosen the best response.1
well, the base would be 10 since we figured that out and aren't we trying to find the height right now?
 one year ago

KingGeorgeBest ResponseYou've already chosen the best response.1
We know that the distance from (7, 2) to (7, b) is b2, and it's a vertical line. What does that tell you about the height of the triangle?
 one year ago

KingGeorgeBest ResponseYou've already chosen the best response.1
dw:1338696349644:dwCan you tell me what the area of this triangle is?
 one year ago

KingGeorgeBest ResponseYou've already chosen the best response.1
In this triangle, the base is of length 10, and the height is b2. Using the formula for the area of a triangle, what do you get as the area?
 one year ago

xRAWRRx3Best ResponseYou've already chosen the best response.1
well, they gave it to us that the area is 45.
 one year ago

dpaIncBest ResponseYou've already chosen the best response.0
can i suggest another method?
 one year ago

xRAWRRx3Best ResponseYou've already chosen the best response.1
ohmigosh ._. what is that? ._.
 one year ago

xRAWRRx3Best ResponseYou've already chosen the best response.1
sorry, but I don't think I learned that LOL
 one year ago

KingGeorgeBest ResponseYou've already chosen the best response.1
Back to the first way then.
 one year ago

KingGeorgeBest ResponseYou've already chosen the best response.1
You're given that the area is 45, the base is of length 10, and the height is b2. Now use your formula of \[A=\frac{1}{2}bh\]with \(b=10\) and \(h=b2\) (those are different \(b\)'s). What do you get?
 one year ago

xRAWRRx3Best ResponseYou've already chosen the best response.1
i don't know why but I got 9.4....
 one year ago

KingGeorgeBest ResponseYou've already chosen the best response.1
I don't know why either :P You should get \[A=45=\frac{1}{2}\cdot10\cdot(b2)=5\cdot(b2)\]
 one year ago

KingGeorgeBest ResponseYou've already chosen the best response.1
Can you solve the equation \[45=5(b2)\]for \(b\)?
 one year ago

xRAWRRx3Best ResponseYou've already chosen the best response.1
yeahh so then that would become: 45 = 5b 10.. OH. OKAY HOLD ON. I MADE A MISTAKE LOL
 one year ago

KingGeorgeBest ResponseYou've already chosen the best response.1
Perfect. Great job.
 one year ago

xRAWRRx3Best ResponseYou've already chosen the best response.1
OHMIGOSH THANK YOU SO MUCH :D YOU HELPED ME SO MUCH THANK YOU THANK YOU THANK YOU THANK YOU THANK YOU :D
 one year ago

dpaIncBest ResponseYou've already chosen the best response.0
here is the thing that i was suggesting to find the area of a triangle using matrices: http://www.youtube.com/watch?v=a5C_I5Fywfo
 one year ago
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