Trigonometric Circle Board 260mm. x 260mm. x 10mm. thick wooden card board .120mm. bottom and 120mm. left side take the center of the board and center to circular dials 200mm. circular groove 5mm. x 6mm. depth. X and Y marking in the dials. Full protractor 360 marking center and 5 to 10 marking out side of dials dia 5mm.x 6mm. hole in the center and top of circular board locating.                                                                                                                           Quantity 01