$\displaystyle\Delta{A}{B}{C}\usepackage{cmbright}\Huge\$ ~ $\displaystyle\Delta{D}{E}{F}\usepackage{cmbright}\Huge\$ because $\displaystyle\frac{{6}}{{4}}=\frac{{12}}{{8}}=\frac{{9}}{{6}}\usepackage{cmbright}\Huge\$