Incorrect. Remember that the sum of the three angles of a triangle is $\displaystyle{{180}}^{\circ}\usepackage{cmbright}\Huge\$ . So you need to solve the equation $\displaystyle{{56}}^{\circ}+{{63}}^{\circ}+{{x}}^{\circ}={{180}}^{\circ}.\usepackage{cmbright}\Huge\$