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xRAWRRx3
Group Title
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?
 2 years ago
 2 years ago
xRAWRRx3 Group Title
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?
 2 years ago
 2 years ago

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KingGeorge Group TitleBest 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)?
 2 years ago

KingGeorge Group TitleBest ResponseYou've already chosen the best response.1
Perfect. Now what's the formula for area of a triangle?
 2 years ago

xRAWRRx3 Group TitleBest ResponseYou've already chosen the best response.1
A = 1/2 base times height?
 2 years ago

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

KingGeorge Group TitleBest ResponseYou've already chosen the best response.1
And assuming b is positive.
 2 years ago

xRAWRRx3 Group TitleBest 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.
 2 years ago

KingGeorge Group TitleBest 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. \[\sqrt{(b2)^2+(77)^2} =\sqrt{(b2)^2}=b2\]
 2 years ago

xRAWRRx3 Group TitleBest ResponseYou've already chosen the best response.1
yeah, that's what I tried to do.
 2 years ago

KingGeorge Group TitleBest 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.
 2 years ago

xRAWRRx3 Group TitleBest ResponseYou've already chosen the best response.1
mhmm, then?
 2 years ago

KingGeorge Group TitleBest ResponseYou've already chosen the best response.1
One last thing. What's the base and the height of the triangle?
 2 years ago

xRAWRRx3 Group TitleBest 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?
 2 years ago

KingGeorge Group TitleBest 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?
 2 years ago

xRAWRRx3 Group TitleBest ResponseYou've already chosen the best response.1
It's perpendicular?
 2 years ago

KingGeorge Group TitleBest ResponseYou've already chosen the best response.1
dw:1338696349644:dwCan you tell me what the area of this triangle is?
 2 years ago

xRAWRRx3 Group TitleBest ResponseYou've already chosen the best response.1
5b  10? ._. idk...
 2 years ago

KingGeorge Group TitleBest 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?
 2 years ago

xRAWRRx3 Group TitleBest ResponseYou've already chosen the best response.1
well, they gave it to us that the area is 45.
 2 years ago

dpaInc Group TitleBest ResponseYou've already chosen the best response.0
can i suggest another method?
 2 years ago

KingGeorge Group TitleBest ResponseYou've already chosen the best response.1
Go ahead.
 2 years ago

xRAWRRx3 Group TitleBest ResponseYou've already chosen the best response.1
ohmigosh ._. what is that? ._.
 2 years ago

xRAWRRx3 Group TitleBest ResponseYou've already chosen the best response.1
sorry, but I don't think I learned that LOL
 2 years ago

KingGeorge Group TitleBest ResponseYou've already chosen the best response.1
Back to the first way then.
 2 years ago

xRAWRRx3 Group TitleBest ResponseYou've already chosen the best response.1
LOL sorry, dpalnc :(
 2 years ago

KingGeorge Group TitleBest 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?
 2 years ago

xRAWRRx3 Group TitleBest ResponseYou've already chosen the best response.1
i don't know why but I got 9.4....
 2 years ago

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

KingGeorge Group TitleBest ResponseYou've already chosen the best response.1
Can you solve the equation \[45=5(b2)\]for \(b\)?
 2 years ago

xRAWRRx3 Group TitleBest 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
 2 years ago

xRAWRRx3 Group TitleBest ResponseYou've already chosen the best response.1
B = 11 !!!
 2 years ago

KingGeorge Group TitleBest ResponseYou've already chosen the best response.1
Perfect. Great job.
 2 years ago

xRAWRRx3 Group TitleBest 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
 2 years ago

KingGeorge Group TitleBest ResponseYou've already chosen the best response.1
You're welcome :)
 2 years ago

dpaInc Group TitleBest 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
 2 years ago
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