I am struggling thinking it is either the first or third one. Hope I narrowed it down a bit.
We'll use the following properties of sine and cosine to prove this:



Then it's just a matter of filling it in...
sin20sin40 * sin60sin80 = 1/2(cos20 - cos60) * 1/2 (cos20 - cos140) =
1/8( cos40 + 1 - cos160 - cos120 - cos40 - cos80 + cos80 + cos200) =
1/8(1 - cos160 - cos120 + cos200) =
1/8(1 - cos160 - cos120 + cos160) =
1/8(1 - cos120 ) = 1/8( 1 + 1/2 ) = 3/16
Mike´s salary=x
Ron´s salary=2x
We can suggest the following equation:
x+2x=441
3x=441
x=441/3
x=147
Mike´s salary=147
Ron´s salary=2x=2(147)=294
Answer: Ron´s salary is $294 and Mike´s salry is $147.
You have a bunch of interesting figures there (check the diagram):
- square (in red)
- parallelogram (in green)
- Isosceles trapezoid (in yellow)
- Isosceles triangles (blue, and purple)
Notice that you have more than one of the same figures: a bunch of small isosceles triangles, tow isosceles trapezoids, two big isosceles triangles... etc.