A blade includes a root to be mounted in a slot of plural slots which open out at an outer periphery of a rotor disk of a movable wheel of a low-pressure turbine of an aeronautical propulsion system, the rotor disk being centered on a longitudinal axis and the slots being circumferentially distributed about the longitudinal axis, the rotor disk having an upstream surface and a downstream surface, each slot being delimited by a bottom surface, the rotor disk including blades circumferentially distributed at the outer periphery of the rotor disk, each blade being mounted in a corresponding slot, the root including a first platform which has a radially outer surface; a shroud having a second platform which has a radially inner surface; and an airfoil extending from the root to the shroud, the airfoil having a leading edge and a trailing edge.