Question

find are a of triangle formed by points ( 2 , 3 ) , ( -1 , 0 ) , ( 2 , -4 ) ​

Answer 1

Answer:

Step-by-step explanation:

If you have a good-enough visual imagination (or if you draw a sketch) you’ll realize that the triangle aligns nicely with the axes. (The A and C vertices have the same x-coordinate, making one side vertical; and the B coordinate is on the x-axis) So we have two right-angles triangles glued together. One with area 12×3×3=4.5 and the other with area 12×3×4=6. So the area is 10.5.

If you can’t visualize, and have no pencil, or are devoted to algebra, then you can use Heron’s Method…

|AB|=32+32−−−−−−√=18−−√

|BC|=32+42−−−−−−√=5

|AC|=02+72−−−−−−√=7

So the semi-perimeter is  s=7+5+18√2=8.121320344