This question has this set of answer choices:
a) when the plane cuts three faces of the cube, separating one corner from the others
b) when the plane passes through a pair of vertices that do not share a common face
c) when the plane is perpendicular to the base and intersects two adjacent vertical faces
d) when the plane makes an acute angle to the base and intersects three vertical faces
e) not enough information to answer the question
The right answer is the first choice: a) when the plane cuts three faces of the cube, separating one corner from the others
You can see a picture of this case in the figure attached: as you can see the cross section (in pink) is a triangle.
Hey!
So the first thing we realize is that it says that the equation is perpendicular to the line, meaning that the slope of the line is the negative reciprocal of the slope of the line you are given. Since we are given the slope of this line as 3/4 we can take the negative reciprocal of this to get -(4/3).
Now that we have the slope and a point on the line you can plug those into the equation y = mx + b to find b. The slope of the line is m and the point contains the x and y values.
5 = -(4/3)(-3) + b
5 = 4 + b
1 = b
Since we have the y-intercept and the slope now we can plug that into the slope-intercept form equation to get the equation we need:
y = -(4/3)x + 1
Use subtraction the answer is 44
B. 2 …………………………,.,,,,,.,.,.,.,.,,,.,