BLADE, ROTARY MACHINE AND GAS TURBINE INCLUDING SAME, AND BLADE INSTALLATION METHOD

A blade(1330, 2300, 4300) for a rotary machine(1300) includes an airfoil(1331, 2310, 4310) having a leading edge(LE) and a trailing edge(TE), a root part(1335, 2350) located at a lower portion of the airfoil(1331, 2310, 4310), and a platform part(1332, 2320, 4320) located between the root part(1335, 2350) and the airfoil(1331, 2310, 4310) and having a first side surface(S1) and a second side surface(S2) spaced apart from each other. The first side surface(S1) includes a first reference surface(S11) and a first inclined surface(S12) formed inclined to the first reference surface(S11), and the second side surface(S2) includes a second reference surface(S21) and a second inclined surface(S22) formed inclined to the second reference surface(S21).