3. Given that $E$ is a point on the side $BC$ of square $ABCD$, such that $S_{\triangle ABE} 、 S_{\triangle AEC} 、 S_{\triangle ACD}$ form a geometric sequence. Then $\angle EAB=$ $\qquad$ (accurate to $1^{\prime \prime}$ ).
3. $20^{\circ} 54^{\prime} 19^{\prime \prime}$