[tex]\begin{gathered} \text{Triangle area =}\frac{base\cdot high}{2} \\ AreaTriangle\text{ }1=\frac{5\cdot high}{2}=2.5\text{high} \\ \\ AreaTriangle\text{ }2=\frac{8\cdot high}{2}=4\text{high} \\ \\ ratio=\frac{AreaTriangle\text{ }2}{AreaTriangle\text{ }1} \\ \\ S\text{upposing both triangles have the same high} \\ ratio=\frac{4\text{high}}{2.5\text{high}}=1.6 \\ The\text{ ratio of areas is 1.6} \\ \\ \text{If the smaller triangle is 15 in}^2 \\ ratio=\frac{AreaTriangle\text{ }2}{AreaTriangle\text{ }1} \\ \\ AreaTriangle\text{ }2=ratio\cdot AreaTriangle\text{ }1 \\ AreaTriangle2=1.6\cdot\text{15 in}^2 \\ AreaTriangle2=\text{ 24 in}^2 \\ \text{The area of the larger triangle is 24 in}^2 \end{gathered}[/tex]