1.  Reply With Quote

2.

3. Let's go through this step by step...can you find the area of $\displaystyle \triangle ABC$ ?  Reply With Quote Originally Posted by MarkFL Let's go through this step by step...can you find the area of $\displaystyle \triangle ABC$ ?
3200cm^2  Reply With Quote

5. Originally Posted by Yazan975 3200cm^2
That's not correct...how did you arrive at that answer?  Reply With Quote Originally Posted by MarkFL That's not correct...how did you arrive at that answer?
1600cm^2?

For 3200 I multiplied Base and Height but didn't divide by 2  Reply With Quote

7. Originally Posted by Yazan975 1600cm^2?

For 3200 I multiplied Base and Height but didn't divide by 2
Okay, good...so what must the area of $\displaystyle \triangle AED$ be?  Reply With Quote Originally Posted by MarkFL Okay, good...so what must the area of $\displaystyle \triangle AED$ be?
xy/2 cm^2  Reply With Quote

9. Originally Posted by Yazan975 xy/2 cm^2
Yes, that's correct in terms of $$x$$ and $$y$$, but we should also be able to assign a numeric value to its area based on the fact that the areas of the two shaded regions are the same. This will give us an equation...can you state it?  Reply With Quote Originally Posted by MarkFL Yes, that's correct in terms of $$x$$ and $$y$$, but we should also be able to assign a numeric value to its area based on the fact that the areas of the two shaded regions are the same. This will give us an equation...can you state it?
xy/2 cm^2 = 800
xy = 1600

Is that right?  Reply With Quote

11. Originally Posted by Yazan975 xy/2 cm^2 = 800
xy = 1600

Is that right?
Excellent! Okay, now the next thing I notice is that within $\displaystyle \triangle ABC$ there are two similar triangles, with $\displaystyle \triangle AED$ being the smaller of the two. This means we may state:

$\displaystyle \frac{y}{x}=\frac{40}{x+10}$

Do you see where this comes from?

What I would do here is solve both equations we now have for $$y$$, and equate the two results to get an equation in $$x$$...can you state this equation?  Reply With Quote

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