Question

The area of the triangle whose adjacent sides are represented by the vector $(4\overline{i}+3\overline{j}+4\overline{k})$ and $5\overline{i}$ in square units is:

• A. $25$
• B. $12.5$
• C. $50$
• D. $45$

Answer 1

Answer: (B)

$12.5$

Area $=\frac{1}{2}\times |A\times B|$
$A\times B$ $=15k-20j$
$|A\times B|$ $=25$
$⟹$ Area $=$ $12.5$