Calculate the area of the triangle for which two of its sides are given by the vectors `vecA=5hati-3hatj, vecB=4hati+6hatj`.

Explanation

Area of the triangle `=(1)/(2)|barAxxbarB|`
`barAxxbarB=|{:(hati,hatj,hatk),(5,-3,0),(4,6,0):}|=hati(0)+hatj(0)+hatk(30+12)=42hatk`
`|barAxxbarB|=sqrt(42^(2))=42`
`:.` Area of the triangle `=(1)/(2)|barAxxbarB|=(1)/(2)xx42` Area =21 squared units