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Printjmc
algebra intermediate
Problem
A line with slope equal to and a line with slope equal to intersect at the point as shown.
What is the area of
Solution
The slope of line segment is Since the "rise" of is units, the "run" of should also be units. Therefore, is units horizontally to the left of and so has coordinates
The slope of line segment is Since the rise of is units, then the run of is units. Therefore, is units horizontally to the left of and so has coordinates
(We could have used the coordinates of and the slopes of the lines to find that the equations of the lines are and and used them to find the coordinates of and )
Therefore, and is units above the -axis. Thus, treating as the base of we find that its area is
The slope of line segment is Since the rise of is units, then the run of is units. Therefore, is units horizontally to the left of and so has coordinates
(We could have used the coordinates of and the slopes of the lines to find that the equations of the lines are and and used them to find the coordinates of and )
Therefore, and is units above the -axis. Thus, treating as the base of we find that its area is
Final answer
9