The area of a parallelogram whose diagonals are d1 and d2 is given by:
Area=21∣d1×d2∣
Find the diagonals:
d1=b+c=(2i^−3j^+k^)+(−i^+k^)=i^−3j^+2k^
d2=a+c=(2j^−k^)+(−i^+k^)=−i^+2j^Compute the cross product:
d1×d2=i^1−1j^−32k^20=−4i^−2j^−k^Calculate the area:
∣d1×d2∣=(−4)2+(−2)2+(−1)2=21
Area=221 sq. units