These problems are simple to solve once you know what you're looking for! All you're going to need is a protractor which is something almost every classroom has. You can also print one offline if you're currently at home. Line up the little hole in the bottom of the protractor with the point in the angle on your paper. The 0 degree line should also be matching up with the bottom angle line. Then looking at the line at the top of your angle, see to what number that line is pointing to.
Assuming the frame is rectangular, the perimeter is 2*width + 2*length. so 5*2 + 2*length = 24. subtract ten from both sides to get the 14 = 2*length. the length = 7.
