Water waves having parallel crests $4\mathrm{.}7$ cm

apart pass through two openings $7\mathrm{.}7$ cm

apart in a board.

Part A

Part complete

At a point $3\mathrm{.}0$m

beyond the board, at what angle$($s$)$

$(0<$$<90)$

relative to the "straight$-$through" direction would there be little or no wave action?