How to compute the area and the distance?

I can solve for AB and AC, but I don't know how to get the area and distance by using AB and AC.

Answer 1

[KSSV]

Area can be computed using area or by writitng your own formula.

Distance can be calculated using the formula.

Tp get distance between point and plane you have the formula.

https://mathinsight.org/distance_point_plane#:~:text=The%20shortest%20distance%20from%20a,as%20a%20gray%20line%20segment.