Because thee dimensions of ΔRAH is twice as large as corresponding dimensions of ΔEAC,
|RA|=2|EA|=2*3.5=7
|AH|=2|AC|=2*6=12
So, we have that 2 corresponding sides are in proportion and angle between them =90⁰, so the angle between them are congruent,
we can use SAS to prove that these triangles are similar.
The answer will be 29,000
In order to prove

Let's write both sides in terms of
only.
Let's start with the left hand side: we can use the formula for sum and subtraction of the sine to write

and

So, their multiplication is

So, the left hand side simplifies to

Now, on with the right hand side. We have

Now simply make this expression one fraction:

And as you can see, the two sides are equal.
31 + (4*2^2 + 8*2) + (3*2^2 + 5*2 + 20) + (7*2 + 30) = 129
3/4 y= 24
Multiply both sides of the equation by 4/3 (the reciprocal of 3/4) to be left with y.
4/3 × 3/4y = 24 × 4/3
y = 24 × 4/3
y = 32
Hope this helps!