Question

Help please!
Fan and medal!

http://prntscr.com/3d1o3s

Answer 1

Well, first your going to have to find the area of the rectangle, then find the area of the triangle, then find out what fraction it is of the rectangle...

Answer 2

So wouldn't it be like (2 + x) * x ?

Answer 3

You have to divide the area of the triangle by the area of the rectangle.

Answer 4

I know it's base times height for the rectangle.

Answer 5

Try to use the numbers given in the drawing:

Rectangle: you already calculated its area.
How do you calculate the area of a triangle?

Answer 6

½ × b × h

Answer 7

So you have \(\frac{1}{2}\cdot x \cdot 2=x\) for the area of the triangle.
Now divide the two.

Answer 8

area of rectangle = x*(x+2)

the shaded area consists of two right triangles, both with height 2, and base 1/2x
left right triangle =.5(.5x*2)
right right triangle =.5(*.5x*2)

add those two together

then:
area of two right triangles/area of rectangle=answer

Answer 9

Maybe this clears it up:

\(\dfrac {AreaOfTriangle}{AreaOfRectangle}=\dfrac{\frac{1}{2}\cdot x \cdot 2}{(x+2)\cdot x}=\dfrac{x}{(x+2)\cdot x}=\dfrac{1\cdot x}{(x+2)\cdot x}=...\)

Try to simplify...

Answer 10

Yeah, but would I be able to answer it even if I don't know what x is?

\[\frac{ x }{ 2x + 2x } = \frac{ x }{ 4x }\]

Answer 11

You made a mistake in the denominator: \((x+2)\cdot x=x^2+2x\).
But you can do something else: divide both numerator and denominator by x.

Answer 12

So it would be \[x ^{2} \times x\]

Answer 13

No, \(\dfrac{1 \cdot x}{(x+2)\cdot x}=\dfrac{1}{x+2}\), because we have divided top and bottom by x.

Answer 14

You are not supposed to calculate x. That cannot be done.
The answer we have, is the answer to the question. As soon a you should pick a value for x, say x=2, you can calculate the fraction as 1/4 so in that case, the triangle's area is one quarter of that of the rectangle.

Answer 15

Ohh I understand it now.

Answer 16

BTW, dividing by an unknown number (x) is dangerous, because what if it should be 0?
Then you certainly can not divide by it.
Here that is not a problem: we know for sure that x > 0, otherwise there would be no rectangle...

Answer 17

Oh I've had that mistake a few times, but this really helped.

Answer 18

BTW2: sorry for my English (native Dutch speaker here).

Answer 19

And YW!

Answer 20

Oh no no you're absolutely fine xD I'm Hispanic xD