Solve for the indicated variable.

a + b + c = 180

Solve for b.

subtract (a+c) from both sides:

b = 180 - (a+c)

To solve for the indicated variable, we need to determine the value of one of the variables in terms of the other variables. In this case, we are given that a + b + c = 180. Since we do not have any specific variable indicated, we can choose any of the variables to solve for.

Let's solve for variable a:

a + b + c = 180

To isolate variable a, we need to get rid of b and c on the left side of the equation. We can do this by subtracting both b and c from both sides. This will result in:

a = 180 - b - c

Now, we have solved for variable a in terms of variables b and c. If you have a specific value for b and c, you can substitute those values into the equation to get the value of a.

Similarly, if you want to solve for b or c, you can follow the same steps and adjust the equation accordingly.