 Which Height Metres / feet has a Rank of 8, and Floors of 3x17?
CREATE TABLE table_74823 (
    "Rank" real,
    "Name" text,
    "Location" text,
    "Height Metres / feet" text,
    "Floors" text
)
SELECT "Height Metres / feet" FROM table_74823 WHERE "Rank" = '8' AND "Floors" = '3x17'