The answer is 535.96mm squared. To find surface area do length times width plus length times height plus width times height and then you multiply it by 2. You are basically finding the area of all the faces and adding them together.
The first step to do is to figure out what angle the perpendicular would be at:
Considering that line s has a slope of 1, then line t would have a slope of -1
<em>A </em>perpendicular line is the inverse of the original line, giving it an angle of 90° where they intersect. You'll find it by flipping the numerator and denominator of a fraction them making it negative.
The next step is to line it up with the point (1,2). The y-intercept does not change when you're making a line perpendicular.
So the equation so far is y = -x -8, <u>note that's not the answer</u>
The last step is to simply use logic, as if a line needs to intersect with a point on a graph, you can just backtrack.
Knowing that each x value that you move forward on the graph, the you go down 1 on the y axis, by using 3 as the y-intercept, you're on the right track.
By using (0,3) as the y-intercept, and moving right 1 and then down 1 (to match with line t's slope), you'll get to the point (1, 2)