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Junior Member
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Oct 4, 2008, 06:20 AM
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I can't figure these three math problems out!
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Ultra Member
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Oct 4, 2008, 07:48 AM
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For the first one, about the easiest way is to find the area of the white region and subtract from the total area of the rectangle.
Given the smaller shaded triangle, find the height of the rectangle by using Pythagoras.
Then you have all the info to answer the question.
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Junior Member
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Oct 4, 2008, 09:44 AM
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Originally Posted by galactus
For the first one, about the easiest way is to find the area of the white region and subtract from the total area of the rectangle.
Given the smaller shaded triangle, find the height of the rectangle by using Pythagoras.
Then you have all the info to answer the question.
That doesn't help at all!
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Full Member
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Oct 4, 2008, 09:45 AM
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These are very simple, but if you are looking for help glad to give it, but if you are looking for answers than don't bother
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Ultra Member
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Oct 4, 2008, 02:48 PM
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hey I'm not in this hunt, ust curious,
would the third one be:
Xsquared+xsquared= 16squared?
I've not had geometry in 40 years, this brought back bad memories. Lol
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New Member
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Oct 5, 2008, 11:28 AM
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Like the others have said... use the pythagorean theorum (sp?), use it to fine triangle ABE first. WHen you find the missing side length (side AE) it is equal in length to side CD... take the pythagorean theorum and find the area of triangle BCD.. add the two areas together and that will be the totally shaded area.. good luck
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New Member
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Oct 5, 2008, 11:31 AM
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Wait... just re-read the question.. you just need to use the theorum to find side lenth AE.. with that you will have your height and use the area formula for triangles (base*height)/2... you also use the length of AE for CD.. same formula.. add the sides.. wala
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Uber Member
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Oct 5, 2008, 10:08 PM
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Quicker that way for the first question. Do you know that the area of a triangle is basically half the area of a rectangle? You have the dimensions of the rectangle, as AB + BC (5+10 = 15), and by pythagoras', you have AE (
So, area of the triangle (both shaded and unshaded have the same area) is (0.5 x 12 x 15)= 90cm^2.
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Uber Member
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Oct 5, 2008, 10:11 PM
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Second, use Area = 0.5 x Base x Height to find the base.
48 = 0.5 x base WZ x 8
WZ = 12.
Then perimeter = sum of all sides.
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Uber Member
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Oct 5, 2008, 10:14 PM
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Third,
Originally Posted by parttime
hey I'm not in this hunt, ust curious,
would the third one be:
Xsquared+xsquared= 16squared?
I've not had geometry in 40 years, this brought back bad memories. lol
Yes, it's
Therefore
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Junior Member
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Oct 6, 2008, 05:07 AM
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Originally Posted by Unknown008
Third,
Yes, it's
Therefore
Thank you so much! Your answer was the only one that actually helped!
Can you help me with this one? I can't seem to figure it out.
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Junior Member
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Oct 6, 2008, 05:10 AM
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Originally Posted by Unknown008
Quicker that way for the first question. Do you know that the area of a triangle is basically half the area of a rectangle? You have the dimensions of the rectangle, as AB + BC (5+10 = 15), and by pythagoras', you have AE (
So, area of the triangle (both shaded and unshaded have the same area) is (0.5 x 12 x 15)= 90cm^2.
Okay, I understood everything, but the "90cm^2" part. What does "^2" mean? :confused:
Sorry, I'm dumb. /:
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Junior Member
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Oct 6, 2008, 05:15 AM
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Originally Posted by Unknown008
Second, use Area = 0.5 x Base x Height to find the base.
48 = 0.5 x base WZ x 8
WZ = 12.
Then perimeter = sum of all sides.
12 is the answer I got, but I'm not sure if that's the official answer. I understand what you put, but I don't understand if there is another step I have to take. Or if 12 is just the answer.
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Full Member
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Oct 6, 2008, 03:11 PM
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With your last problem, you can simply put in values for each equation and solve. According to the balloon stats, the equation has to equal 44 when t = 3. So let's try 3.
1) h=60+16t (put in 3) h = 60 + 16 (3) = 60 + 48 = 108 (nope)
2) h=70+6t (put in 3) h = 70 + 6 (3) = 70 + 18 = 88 (NOPE)
3) h=80-4t (put in 3) h = 80 - 4(3) = 80 - 12 = 68 (Nope)
4) h=80-4t^2 (put in 3) h = 80 - 4(3^2) = 80 - 36 = 44 (YES)
5) h=90-14t^2 (put in 3) h = 90 - 14(3^2) = 90 - 126 = -36 (NO)
So only (4) works. That has to be the answer. To be sure, try using 2 and 4 for t... and I did. It works. It is the answer.
BTW, just by observing the answers, you can tell that the answers aren't (1) or (2). Those equations increase as your t value increases. You can also tell it can't be equation (3), because that's a constant decline, where-as the balloon isn't constantly declining. That narrows it down to (4) and (5), but (5) is declining way way way too fast. That should also be obvious. I could tell it was (4) before I even did a single Mathematical computation.
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Full Member
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Oct 6, 2008, 03:12 PM
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Originally Posted by Skyrocket Away
Okay, I understood everything, but the "90cm^2" part. What does "^2" mean? :confused:
Sorry, I'm dumb. /:
^2 means squared.
So 4^2 means 4 squared, which equals 16.
k?
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Full Member
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Oct 6, 2008, 03:15 PM
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Originally Posted by Skyrocket Away
12 is the answer I got, but I'm not sure if that's the official answer. I understand what you put, but I don't understand if there is another step I have to take. Or if 12 is just the answer.
The perimeter is the sum of all sides.
The bottom side is 12.
But then you got to add the other 2 sides.
12 + 10 + 10.
That's the official answer.
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Uber Member
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Oct 7, 2008, 05:01 AM
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I guess EuRa answered all your qyestions qhen I was not here. If you have anymore, don't hesitate to ask. Thanks.:)
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