The value of cotangent is correct, but sine is not. You may have thought that sine was the reciprocal of cosine. You need to use the definitions of cosine and tangent together with the given values to find the sides of a right triangle that would have those ratios. A triangle with $\displaystyle{a}{d}{j}={20}\usepackage{cmbright}\Huge\$ , $\displaystyle{h}{y}{p}={29}\usepackage{cmbright}\Huge\$ , and $\displaystyle{o}{p}{p}={21}\usepackage{cmbright}\Huge\$ will have these ratios. Use this information and the definition to find the value of sine.