The two lines y=x and x=-7 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 answer:  A) 18.5  B) 21.5  C) 24.5  D) 27.5  E) 30.5

Rationale: "the point of intersection is ( - 7 , - 7 ) . the triangle has a base of length 7 and a height of 7 . area = ( 1 / 2 ) * base * height = ( 1 / 2 ) * 7 * 7 = 24.5 the answer is c ."
Answer: C