(setq dr (entget (car (entsel))))
yields
((-1 . <Entity name: 1a70d20>) (0 . "ARC")(330 . <Entity name: 19f9c10>)(5 . "B0DC")
(100 . "AcDbEntity") (67 . 0)(410 . "Model")(8 . "A-DOOR")
(48 . 432.0)
(100 . "AcDbCircle") (10 -4747.88 4580.25 0.0) (40 . 35.9856)
(210 0.0 0.0 -1.0)
(100 . "AcDbArc") (50 . 3.14159)ze (51 . 4.71239)
)
(48 . 432.0)