Answers and Explanations

COORDINATE GEOMETRY FOLLOW-UP TEST

1 . C

The graph   of  x^2     +   y^2     =    169    is  a   circle  centered    at  the origin  and with    a   radius  of  13. The square

of  that    radius  must    equal   the sum of  the squares of  the coordinates of  any point   on  the

circle. Remember,   keep    your    eyes    peeled  for 5-12-13 triangles.  The points  shown   below   are

the only    2   points  on  the circle  where   both    x   and y   are negative    integers.

2 . B

First   find    the three   midpoints.