for (a), determine the side lengths. If it's a right triangle, the area is easy. If not, you can use Heron's formula, or evaluate a.bxc where a,b,c are the vectors for the sides.
for (b) there are several ways to pick D. If ABC is a right triangle, one of those ways will produce a rectangle. Otherwise, not.
7. ABC has vertices A(3,2,-5), B(4,-1,7) and C(-8,3,-6).
a) Determine the area of ABC.
b) Determine the coordinates of point D such that ABCD is a parallelogram.
c) Is the parallelogram a rectangle? Justify your answer.
1 answer
1 answer