Dalitz analysis of the three-body charmless decays<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:msup><mml:mi>B</mml:mi><mml:mo>+</mml:mo></mml:msup><mml:mo>→</mml:mo><mml:msup><mml:mi>K</mml:mi><mml:mo>+</mml:mo></mml:msup><mml:msup><mml:mi>π</mml:mi><mml:mo>+</mml:mo></mml:msup><mml:msup><mml:mi>π</mml:mi><mml:mo>−</mml:mo></mml:msup></mml:math>and<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:msup><mml:mi>B</mml:mi><mml:mo>+</mml:mo></mml:msup><mml:mo>→</mml:mo><mml:msup><mml:mi>K</mml:mi><mml:mo>+</mml:mo></mml:msup><mml:msup><mml:mi>K</mml:mi><mml:mo>+</mml:mo></mml:msup><mml:msup><mml:mi>K</mml:mi><mml:mo>−</mml:mo></mml:msup></mml:math>

We report results on the Dalitz analysis of three-body charmless ${B}^{+}\ensuremath{\rightarrow}{K}^{+}{\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{\ensuremath{-}}$ and ${B}^{+}\ensuremath{\rightarrow}{K}^{+}{K}^{+}{K}^{\ensuremath{-}}$ decays based on a $140{\text{ }\text{ }\mathrm{fb}}^{\ensuremath{-}1}$ data sample collected with the Belle detector. Measurements of branching fractions for quasi-two-body decays to scalar-pseudoscalar states: ${B}^{+}\ensuremath{\rightarrow}{f}_{0}(980){K}^{+}$, ${B}^{+}\ensuremath{\rightarrow}{K}_{0}^{*}(1430{)}^{0}{\ensuremath{\pi}}^{+}$, and to vector-pseudoscalar states: ${B}^{+}\ensuremath{\rightarrow}{K}^{*}(892{)}^{0}{\ensuremath{\pi}}^{+}$, ${B}^{+}\ensuremath{\rightarrow}{\ensuremath{\rho}}^{0}{K}^{+}$, ${B}^{+}\ensuremath{\rightarrow}\ensuremath{\phi}{K}^{+}$ are presented. Upper limits on decays to some pseudoscalar-tensor final states are reported. We also report the measurement of the ${B}^{+}\ensuremath{\rightarrow}{\ensuremath{\chi}}_{c0}{K}^{+}$ branching fraction in two ${\ensuremath{\chi}}_{c0}$ decays channels: ${\ensuremath{\chi}}_{c0}\ensuremath{\rightarrow}{\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{\ensuremath{-}}$ and ${\ensuremath{\chi}}_{c0}\ensuremath{\rightarrow}{K}^{+}{K}^{\ensuremath{-}}$.