



 
Hi Robert, From what you sent your daughter does know what she is doing. She is already working with a variable, n. For example in 41) she starts with 36 = 360/n, multiplies both sides by n to get 36n = 360 and then divides both sides by 36 to obtain n = 10. Then she substitutes n = 10 into the expression for EI to find the measure of the interior angle. For 44) she needs to perform the same steps even though she doesn't know the value of x. The first expression is then
Now, as she did before multiply both sides by n to obtain
Her next step was to divide both sides by the value of x and this gives
This just says that the number of sides is 360 divided by the measure of the exterior angle. Then substitute this value for n into the expression for EI I think I will leave it at this point. This does simplify to become a much nicer expression but I expect that is what they will do next in class. I hope this helps,  


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