Form an equation, but with what? You'll need variables, so make them! (Here is a lovely recipe for variables)
Let:
s = smallest number
m = middle number
l = largest number
But...you can't just add that!
Let's write everything in terms of "m".
s = m - 5
m = m
l = 2m + 3
Now...we add!
m - 5 + m + 2m + 3 = 42
4m - 2 = 42
4m = 44
m = 11
Now, we plug m back into the original variables:
s = 11 - 5 = 6
l = 2(11) + 3 = 25
So, the 3 numbers are [6, 11, 25]
Did you actually press on the link? No recipe? Just a definition? Sorry...have some cookies! (They are up at the top shelf of my pantry...they taste nice, but not as good as Ginger's banana daiquiri! I managed to sneak a sip...hope she doesn't realize!)
:)
We need to sharpen our trig skills, because believe it or not, this problem involves trig!
Anyways, I assume we are allowed to use calculators.
What we need to do is calculate the tangent divided by 7. Maybe you haven't seen the wonders a calculator could do, so I will show you step by step.
1. Tangents!
2. Tangent(35)
3. 7 divided by that:
4. Enter!
There! Rounded, that would be 10
Maybe youll learn how to use calculators ;P, don't we all just love them?
:)
In my opinion, there's no point of that extra triangle, maybe just there as a red herring...
Anyways, we can use the Pythagorean theorem on 12 and 6 to get y.
We know that:
a2 + b2 = c2
Here is a lovely little picture that could help you wrap your mind around how it works:
So, what does this tell us? Well, now we know this now:
122 = 62 + y2
This now means:
144 = 36 + y2
Simplify:
108 = y2
Which means:
y = sqrt(108) = 6sqrt(3)
:)