## College Physics (7th Edition)

The equation for trapezoid area $A=\frac{1}{2}a(b_1+b_2)$ is dimensionally correct.
Equation for area of trapezoid - $A=\frac{1}{2}a(b_1+b_2)$ LHS - $A$ has SI unit $m^2$. RHS - $(b_1+b_2)$ has SI unit $m$. $a$ has SI unit $m$. Their product, thus, has SI unit $m^2$. Both sides have the same units; the equation is dimensionally correct.