How do you calculate area of rectangular duct 90 degree elbow?

To calculate the area of a rectangular duct 90-degree elbow, first determine the cross-sectional area of the duct sections before and after the elbow. Measure the width and height of the duct to find the area using the formula: Area = Width × Height. For the elbow itself, you can typically ignore its contribution to the area, focusing instead on the straight sections, as the elbow primarily changes direction rather than cross-sectional area. Ensure to account for any additional factors like flow dynamics if necessary.