2 angles opposite from each other are vertical angles.
Vertical angles are equal to each other.
Since Y is opposite the given angle of 163 degrees, Y = 163.
Multiply both sides by 7.
-5 * 7 = c/7 * 7
-5 * 7 = c
c = -35
Your final answer is c = -35.
Answer: surface area = area of BASE + 1/2 × perimeter of base × slant HEIGHT.
It is hard to explain without a picture. You have the line graph and depending on what your numbers are, you place them where the teacher, (or paper) says too. You would then move two to the right, and one up. You would keep repeating that pattern until you got to the top of the graph. After that you would draw a strait line through it. If you are dealing with negative numbers, then depending on which one is negative, you would move two to the LEFT from the starting point and go one up. You repeat that pattern as well, then once you reach the top of the page you draw a line through it.
I hope this helped!
~ Maya
