Yes, PERPENDICULARS is a Scrabble word!

Letter values in Scrabble US: P 3, E 1, R 1, P 3, E 1, N 1, D 2, I 1, C 3, U 1, L 1, A 1, R 1, S 1.

Is it a valid word?

PERPENDICULARS is a valid word in the official Scrabble dictionary (US), the UK Scrabble Dictionary and Words with Friends (ENABLE).

a straight line at right angles to another line
a Gothic style in 14th and 15th century England; characterized by vertical lines and a four-centered (Tudor) arch and fan vaulting
a cord from which a metal weight is suspended pointing directly to the earth's center of gravity; used to determine the vertical from a given point
an extremely steep face

Also: perpendicular style, english-gothic, english-gothic architecture, plumb line.