Which sign had a yellow background and a triangular shape?
CREATE TABLE table_57201 (
    "Type of sign" text,
    "Shape" text,
    "Border" text,
    "Background colour" text,
    "Text/Symbol" text
)
SELECT "Border" FROM table_57201 WHERE "Background colour" = 'yellow' AND "Shape" = 'triangular'
Below are sql tables schemas paired with instruction that describes a task. Using valid SQLite, write a response that appropriately completes the request for the provided tables. ### Instruction: Which sign had a yellow background and a triangular shape? ### Input: CREATE TABLE table_57201 (
    "Type of sign" text,
    "Shape" text,
    "Border" text,
    "Background colour" text,
    "Text/Symbol" text
) ### Response: SELECT "Border" FROM table_57201 WHERE "Background colour" = 'yellow' AND "Shape" = 'triangular'