(Solved): We have to find the centriod of different shapes the class example is the teachers work and shown be ...

We have to find the centriod of different shapes the class example is the teachers work and shown below are the 3 shapes and how he found the area, x, y, x•area, y•area, truss b is a new problem and i have seperated it into 8 shapes starting from 1 to 8 i want to find the area, x, y, x•area, y•area using the same format he does. I have already done some which but am pretty sure I made mistakes