Thought I did this right but apparently got it wrong

Printable View

May 10th 2012, 09:18 AM
brokaliv

1 Attachment(s)

Thought I did this right but apparently got it wrong

Attachment 23836
Two strips of cloth with width 1 overlap at an angle a as shown. Find the area of the overlap.

I swear I am missing something on this.

Rhombus Area is base x height
Height is 1
Let base = x

unknown angle a

So all I could come up with was:

$x = 1/sine (a)$

Which gave me the Area = A

$A = 1 * (1/Sine (a))$

I don't recall ever figuring out an area with so little information given before.
May 10th 2012, 11:05 AM
emakarov

Re: Thought I did this right but apparently got it wrong

I agree with your solution.
May 13th 2012, 06:24 AM
Soroban

Re: Thought I did this right but apparently got it wrong

Hello, brokaliv!

If you submitted the answer $A = 1 * (1/Sine (a))$ to an online exam,
. . it probably did not recognize the expression.

. . First of all, sine would be entered/written $\sin$ .

. . Second, $\frac{1}{\sin a}$ is equal to $\csc a.$

. . Third, we never EVER submit an answer like $x \,=\,1\cdot3$ .**

If you submitted that answer to a human teacher/professor,
. . he/she would deduct points for the very same reasons.

~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~

**

Consider this insulting example . . .

. . $\begin{array}{cccccc}\text{Solve for }x\!: & 2x + 3 &=& 9 \\ \\[-3mm] \text{Subtract 3:} & 2x &=& 9 - 3 \\ \\[-4mm] \text{Divide by 2:} & x &=& \dfrac{9-3}{2} \end{array}$

Would you submit $x \,=\,\frac{9-3}{2}\;?$

You are saying, "Hey, I did all the algebra!"
. . followed by, "Oh, did you want me to simplify, too?"