Answer:
Option A
Explanation:
Since,
$(\overrightarrow{a}\times\overrightarrow{b})^{2}+(\overrightarrow{a}.\overrightarrow{b})^{2}$ = 676
(|$\overrightarrow{a}$|.|$\overrightarrow{b}$|$\sin\theta\hat{n}$)2 + (|$\overrightarrow{a}$|.|$\overrightarrow{b}$|$\cos\theta$)2 = 676
|$\overrightarrow{a}$|2 .|$\overrightarrow{b}$|2 ($\sin^{2}\theta+\cos^{2}\theta$) = 676
|$\overrightarrow{a}$|2 (2)2 = 676 = |$\overrightarrow{a}$|2 =169
|$\overrightarrow{a}$|
=13
