Question

if a ( -1 , 3 ) b ( 1 ,-1 ) and c ( 5, 1 ) are the vertices of a triangle find its area ​

Answer 1

Step-by-step explanation:

a ( -1 , 3 ) =(x1,y1),

b ( 1 ,-1 )(x2,y2)

and c ( 5, 1 ) (x3,y3)

are the vertices of a triangle

area of triangle = 1/2 | x1(y2-y3) +x2(y3-y1) +x3(y1-y2) |

area of the triangle= 1/2| -1(-1-1)+1(1-3)+5(3-(-1) |

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

=1/2| 2-2+20 |

=1/2 X 20

= 20 sq units