Note the Desmos Graph that helped me with your answer. Ifyou have any questions you can ask them now.

The green line is
The answer to this question is 51 degrees because that outer angle is the sum of the opposite inner angles. It is the sum of the other angles not touching that angle.
If there were only sandwiches bought, there would be 15, if there were only salads bought there would be 20. There’s probably more than one possibility, but that’s the best I can do, considering how long it’s been since I’ve done this type of problem. I’m all the way to learning determinants, so I really have to think to remember these. Sorry in advance if this doesn’t help at all, I’m not the best at this, but I can still try.
I will use a quadratic formula:
In a rectangle, opposite sides are equal so you can multiply the side lengths by 2 and add them so 16(2)+34(2) and yu get 32+68. The perimeter is 100