Purpose: Section Properties using Geometry and Integration The Home DepotⓇ in Red Hook, Brooklyn is looking to renovate their steel roof truss (Figure 1). They are considering welding a steel plate to the top chord of the truss to improve its strength (Figure 2). You are a staff engineer at a local engineering firm. You have been asked to determine the centroid, moment of inertia, section modulus and radius of gyration of the double angle and plate connection. Your supervisor told you which case to analyze. Directions: Calculations: 1. Sketch the shape to scale using the dimensions from your case number. No Calculations on this page, please. Double angle property dimensions are given in the file "AISC Shape Properties." 2. Please select the bottom center of the given cross-section as an origin of your reference axis. Then calculate: a. Location of the centroid, (x, y) b. Moments of Inertia, I, (in) c. Radius of Gyration, rx (in) (Note: back to back spacing of angles is 1 inch.) Steel plate to be welded onto top chord of existing roof truss One Steel Plate Two Equal Leg Angles Back to Back Figure 1: Existing Roof Truss Section Figure 2: Proposed modification Case No. Equal Double Angles & Plate L-Shape Plate Size 2 L6x6x1 8" x 1"