Answer
(a) $\Phi = 8.7\times 10^{-4}~Wb$
(b) The induced current flows clockwise.
Work Step by Step
(a) We can find the magnetic flux:
$\Phi = B~A$
$\Phi = (B)~(\frac{1}{2}\times \frac{\sqrt{3}}{4}~a^2)$
$\Phi = (0.10~T)~[\frac{1}{2}\times \frac{\sqrt{3}}{4}~(0.20~m)^2]$
$\Phi = 8.7\times 10^{-4}~Wb$
(b) If the magnetic field directed into the page is decreasing, there is less magnetic flux going through the loop. By Lenz's law, a current is induced which opposes the change in flux. Then, the current must produce a magnetic flux directed into the page. By the right hand rule, the induced current flows clockwise.