In this talk, we will introduce the mean width inequalities of sections and projections for isotropic measures with complete equality conditions which is established by a direct approach. This approach contains some techniques like the Ball–Barthe inequality, the mass transportation, and the isotropic embedding. Our result extends the recent work of the mean width about sections and projections of convex bodies in the John (L\"{o}wner) position. To prove our result, a continuous form of the Pr\'{e}kopa-Leindler inequality is provided.