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 most appropriate option.
A) 7.5
B) 10
C) 12.5
D) 15
E) 17.5

Rationale: "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 = 12.5 the answer is c ."
Answer: C