So you need to make out the lengths for the triangle. For the height, you can subtract the short length (100) from the longer length (1250) to get the height of the triangle. The base is the length at the very top, 75. So right now you have 150 for height and 75 for the base. Now use the formula to get 75 root 5.
B = 120 because it is in your sum
Pounds will be represented by x and the cost will be represented by y. The equation is Y=3x. For the graph just use substition for x and then calculate the outcome and graph it.
