The question is asking you to simplify this expression. Since I'm not sure whether or not it wants you to fully solve this or not, I will do both ways.
Just simplifying the expression- 12 squared is about 3.4, and 8 squared is about 2.8. Now the expression is 3.4 x 2.8. Now the equation is simplified.
Simplifying and solving the expression- Now all you have to do if multiply the simplified expression. 3.4 x 2.8 = 9.52
Sorry if this a little off, but I'm not if your teacher wants you to round the decimal a certain way or not. Please let me know if it was right or if you have questions :)
For the first question you just need to add up all the sides. so first add all the x numbers and then add all the plain numbers. a perimeter is the total length around the shape.
