1. anonymous

|dw:1443649213389:dw|

2. anonymous

whats the area

3. anonymous

$x ^{2}+3x-40 ft$

4. anonymous

ft ^2

5. Owlcoffee

The area of any triangle is calculated by: $A _{\triangle}=\frac{ b.h }{ 2 }$ This means, base time height divided by two. Since in the excercise we are given the area $$x^2+3x-40$$ and we know that the base is $$x+8$$, we can then use the formula above by replacing the data: $x^2+3x-40=\frac{ (x+8)(h) }{ 2 }$ Now, it's just a matter to solve for "h".

6. anonymous

So, $(x-5)(x+8)=\frac{ (x+8)(h) }{ 2 }$ Now, what do i do.

7. Owlcoffee

Well, now try to isolate that h on any side of the "=" sign.

8. anonymous

does the (x+8) cancel out?

9. anonymous

@owlcoffee