The two lines y=x and x=-6 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 one:
A) 12
B) 14
C) 16
D) 18
E) 20
The point of intersection is (-6,-6).   The triangle has a base of length 6 and a height of 6.   area = (1/2)*base*height = (1/2)*6*6= 
<gadget id="calculator">(1/2)*6*6</gadget>
<output>18</output>
18   The answer is 18.
<result>D</result>
The two lines y=x and x=-6 intersect on the coordinate plane. What is the value of the area of the figure formed by the intersecting lines and the x-axis?