The two lines y=x and x=-5 intersect on the coordinate plane. What is the value of the area of the figure formed by the intersecting lines and the x-axis? Choose the correct choice from the following choices
A) 7.5  B) 10  C) 12.5  D) 15  E) 17.5
The point of intersection is (-5,-5).   The triangle has a base of length 5 and a height of 5.   area = (1/2)*base*height = (1/2)*5*5= 
<gadget id="calculator">(1/2)*5*5</gadget>
<output>25/2 = around 12.5</output>
12.5   The answer is 12.5.
<result>C</result>
The two lines y=x and x=-5 intersect on the coordinate plane. What is the value of the area of the figure formed by the intersecting lines and the x-axis?