Let's check the dot product .
v.w = 5(4)-2(10) = 20 -20 =0
So the dot product is not 20 . And since the dot product is zero, so they are perpendicular.
And the y component of w is 10.
So correct options are first and third .
You basically use the formula height*base/2 to find the area of the triangle. For instance, let's say a is your chosen base, which has a length of 7. You then use the pythagorean theorem of the right triangle (which is formed by splitting the triangle in half), which is a^2+b^2=c^2, and you substitute half your base for a and the other length (8) for c, which is the hypotenuse of the triangle. Note how this is all being done to find "b", which is the height of the triangle, which will then help you substitute all of your known values into the area formula of a triangle to answer your question. I'm not sure if b=141 degrees would have an impact on this question, but I hope this helped you in some way.
Answer: 
<u>Step-by-step explanation:</u>
(4, 1) & (2, -5)
First, find the slope (m) and then the perpendicular (opposite reciprocal) slope:
Next, find the midpoint of (4, 1) and (2, -5):
Lastly, input the perpendicular slope and the midpoint into the Point-Slope formula to find the equation of the line:
3n + 7 ><span> 4n
-3n -3n
7 > n
n</span> < 7
Every square is a rectangle<span> because it is a quadrilateral with </span>all<span> four angles right angles.</span>
