Centroid of Area Example
Easy DifficultyFE Statics
Find the centroid (center of area) of an L-shaped region made of two rectangles.
Concept
The centroid of a composite area is the weighted average of the centroids of its parts: and , where is the area of part and is the centroid of that part.
Notation: = coordinates of centroid of composite, = area of part i.
Problem
An L-shaped area consists of two rectangles: Rectangle 1 is 6 m wide by 2 m tall with its bottom-left corner at the origin. Rectangle 2 is 4 m wide by 2 m tall, placed so its left edge is at x = 4 m and its bottom edge at y = 2 m (so it sits on top of and to the right of part of rectangle 1). All dimensions in meters.
Find:
Coordinates of the centroid of the composite area.
Given
- Rectangle 1: 6 m × 2 m, bottom-left at (0, 0)
- Rectangle 2: 4 m × 2 m, bottom-left at (4, 2)
Area and centroid of each part
Composite centroid
Final Answer
Centroid: , .