Answer:
= 
Step-by-step explanation:
AS we can see in the figure that a beam or a rod is balanced by a square on right side
while on the left side we have a smaller square and a triangle
Suppose the values written inside it are the weights of the shapes which are making it stable
So
Total on RHS = Total on LHS
Now Total on RHS = Value of bigger square
= 
Total on LHS = Value of smaller sqaure + Value of triangle
= 
Now we know to make this image a balanced one as shown n the figure
Total on RHS = Total on LHS
putting values gives us
= 
which is the required equation