#TI-80 BASIC, 25 bytes - 25% = 18.75 PARAM 2π/ANS->TSTEP "COS T->X1ᴛ "SIN T->Y1ᴛ DISPGRAPH Assumes all settings are set to the default values. Run the program like 5:PRGM_POLYGON (for a pentagon)

It works by drawing a circle with a very low number of steps. For example, a pentagon would have steps of 2π/5 radians.

The window settings are good enough by default, and TMIN and TMAX are set to 0 and 2π, so all we need to change is TSTEP.

TI-80 BASIC, 25 bytes - 25% = 18.75

PARAM
2π/ANS->TSTEP
"COS T->X1ᴛ
"SIN T->Y1ᴛ
DISPGRAPH

Assumes all settings are set to the default values. Run the program like 5:PRGM_POLYGON (for a pentagon)

It works by drawing a circle with a very low number of steps. For example, a pentagon would have steps of 2π/5 radians.

The window settings are good enough by default, and TMIN and TMAX are set to 0 and 2π, so all we need to change is TSTEP.

#TI-80 BASIC, 25 bytes - 25% = 18.75 PARAM 2π/ANS->TSTEP "COS T->X1ᴛ "SIN T->Y1ᴛ DISPGRAPH Assumes all settings are set to the default values. Run the program like 5:PRGM_POLYGON (for a pentagon)

It works by drawing a circle with a very low number of steps. For example, a pentagon would have steps of 360/5, or 72 degrees.

#TI-80 BASIC, 25 bytes - 25% = 18.75 PARAM 2π/ANS->TSTEP "COS T->X1ᴛ "SIN T->Y1ᴛ DISPGRAPH Assumes all settings are set to the default values. Run the program like 5:PRGM_POLYGON (for a pentagon)

It works by drawing a circle with a very low number of steps. For example, a pentagon would have steps of 2π/5 radians.

The window settings are good enough by default, and TMIN and TMAX are set to 0 and 2π, so all we need to change is TSTEP.

#TI-80 BASIC, not sure how big FNOFF INPUT "SIDES ",S PARAM:DEGREE -1.55->XMIN 1.55->XMAX -1.15->YMIN 1.15->YMAX 0->TMIN 360->TMAX 360/S->TSTEP "SIN T->X1T "COS T->Y1T DISPGRAPH PAUSE DISP " I don't have my calculator with me to test this, so I can't get the size or make it shorter right now.

It works by drawing a circle with a very low number of steps. For example, a pentagon would have steps of 360/5, or 72 degrees.

#TI-80 BASIC, 25 bytes - 25% = 18.75 PARAM 2π/ANS->TSTEP "COS T->X1ᴛ "SIN T->Y1ᴛ DISPGRAPH Assumes all settings are set to the default values. Run the program like 5:PRGM_POLYGON (for a pentagon)

It works by drawing a circle with a very low number of steps. For example, a pentagon would have steps of 360/5, or 72 degrees.