A1. What is the area of the triangle whose vertices are at the vertex and the intersections of the graph of the quadratic function $f(x)=x^{2}-4 x-5$ with the x-axis?
(A) 15
(B) 18
(C) 24
(D) 27
(E) 30
A1. The zeros of the quadratic function are $x_{1}=5$ and $x_{2}=-1$, and the vertex is $T(2,-9)$. The area of the triangle formed by these points is $S=\frac{6 \cdot 9}{2}=27$.