find the area of a triangle whose vertices are a(1,3)b(2,5)c(3,4).

1/2 * | x1(y2-y3)+x2(y3-y1)+x3(y1-y2) |

= 1/2 * | 1(5-4) + 2(4-3) + 3(1-2) |

= 1/2 * | 1 + 2 -3 |

=0.

The area of triangle is '0' therefore the points are collinear and no triangle can be formed.