  Noting the hierarchy between three mixing angles, $\theta_{2,3}={\cal
O}(\theta_1^2)$, we present an exact form of the quark mixing matrix, replacing
Wolfenstein's approximate form. In addition, we suggest to rotate the unitarity
triangle, using the weak CP phase convention where the phase is located at the
(31) element $\sin\theta_1\sin\theta_2 e^{i\delta}$ while the (13) element
$\sin\theta_1\sin\theta_3$ is real. For the $(ab)$ unitarity triangle, the base
line (x-axis) is defined from the product of the first row elements,
$V_{1a}V^*_{1b}$, and the angle between two sides at the origin is defined to
be the phase $\delta$. This is a useful definition since every Jarlskog
triangle has the angle $\delta$ at the origin, defined directly from the
unitarity condition. It is argued that $\delta$ represents the barometer of the
weak CP violation, which can be used to relate it to possible Yukawa textures.
