You may have chosen this answer because the sum of the two numbers is the same as the sum of the two numbers in the measurements of the first triangle. However, the numbers need to satisfy $\displaystyle{y}=\frac{{k}}{{x}}\usepackage{cmbright}\Huge\$ , an inverse variation equation. For the first triangle, $\displaystyle{10}=\frac{{k}}{{6}}\usepackage{cmbright}\Huge\$ , so $\displaystyle{k}={60}\usepackage{cmbright}\Huge\$ . Substitute 8 and 8.

$\displaystyle{8}=\frac{{k}}{{8}}\usepackage{cmbright}\Huge\$ does not yield $\displaystyle{k}={60}\usepackage{cmbright}\Huge\$ , so this is not an inverse relationship.