PDA

View Full Version : Geometry Help


EggNest
Oct17-04, 02:24 PM
Hello everyone,

I need help with a couple of problems, right now I'm focusing on number 25.

http://img24.exs.cx/img24/2291/probs.gif

Also, if any of you have time, could you please tell me if I have missed any so far. Thanks.

22. A= 3768.2 units^2
23. A= 25.3 units^2
24. A= 5.4 units^2

And now if I could just get some help with the others...

arildno
Oct17-04, 02:27 PM
Now, you've got a square with the diagonal given, right?
So, what's your problem, exactly?

EggNest
Oct17-04, 02:29 PM
Now, you've got a square with the diagonal given, right?
So, what's your problem, exactly?
I need help going about finding the lenght of the sides

arildno
Oct17-04, 02:34 PM
Sure enough, but:
1) You've got a square, right?
So, how does then the vertical side compare in length to the horizontal side?
2) Try to set up Pythagoras' theorem with the diagonal as the hypotenuse..

EggNest
Oct17-04, 02:45 PM
The lenght of all the sides would be 7.5 sqrt(2) right?

Tom McCurdy
Oct17-04, 03:02 PM
We have C from Pythagoras' therom
a^2 + b^2 = c^2

however for a square
a=b

so
a^2 + a^2 = c^2
2a^2=c^2

2a^2=15^2
2a^2=225


since area of a square is just a*b and a=b
area equals a*a or a^2 so divide the two out
a^2=\frac{225}{2}

Tom McCurdy
Oct17-04, 03:09 PM
I believe 22 is wrong
23 is right rounded
24 is right rounded

Tom McCurdy
Oct17-04, 03:11 PM
22. by law of sines

\frac {73}{\sin{\theta}}=\frac{x}{\sin{\theta}}

therefore must also be 73
73*73*.5 = 2664.5