The terminal side of $\displaystyle{{100}}^{\circ}\usepackage{cmbright}\Huge\$ lies in Quadrant II where x is negative and y is positive, so $\displaystyle{\sin{\theta}}={y}\usepackage{cmbright}\Huge\$ is positive and $\displaystyle{\tan{\theta}}=\frac{{y}}{{x}}=\frac{{{\left(+\right)}}}{{{\left(-\right)}}}\usepackage{cmbright}\Huge\$ is negative.