The rectangle on the right is 81 and the rectangle on the left is 24. I don't really know about the second one sorry, but I hope this helped.
2 and 3 are both parallel because both slopes are m=3/5, which equal slopes-parallel lines
There is a trig identity called the sum of 2 angles for sin its<span>
sin(a+b)=sin(a)cos(b)+cos(a)(sin(b)
</span>
You will need to use it. So in your question split the 4x in 2 equal parts 2x and 2x
<span>
</span><span>sin(4x)=sin(2x+2x)
</span>Now using the expansion above you will get
<span>sin(2x+2x)=sin(2x)×cos(2x)+cos(2x)×sin(2x)
</span>And it will simplify to
<span><span>2sin(2x)cos(2x)
I hope this helps you! Good luck :)</span></span>
