  We construct petal diagrams from simple braids. This approach allows us to
confirm a conjecture proposed by Kim, No and Yoo, which states that the petal
number of the nontrivial torus knot $T_{r,s}$ ($r<s$) is at most
$2s-2\lfloor\frac{s}{r}\rfloor+1$. As a consequence, we deduce that the petal
number of a nontrivial torus knot $T_{r,s}$ is equal to $2s-1$ if and only if
$r<s<2r$.
