## Geometry: Common Core (15th Edition)

$\frac{3a}{20}$
Use the formula for the area of a rectangle: $A=bh=(\frac{2a}{5b})(\frac{3b}{8})=\frac{6ab}{40b}=\frac{(/\!\!2)(3)a/\!\!b}{(/\!\!2)(20)/\!\!b}=\frac{3a}{20}$