A contractor has 75 feet of safety rail. The foreman is going to install it in such a way that the work area is divided into two congruent rectangles. The table represents the total fenced area, a(s), depending on the length of the shared side, s. The equation a(s) = 37.5s − 1.5s2 models the function represented in the table. Fill in the blank to complete the restricted domain of the function. D = {0 ≤ s ≤ }

Okay so for every triangle has three angles that always add up to 180 degrees. and to tell the difference between whether they are secure, right or obtuse is that acute: has one angle that is less than 90 degrees. right triangle means there is at least one angle that is exactly 90 degrees. and an obtuse angle has an angle that is bigger than 180 degrees. i’ll do #13 as an example: 13. 40 and 50 so if every triangle has 180 degrees 40+50= 90 degrees then180-90= 90 degrees so the third angle is 90 degrees and because this triangle has a 90 degree angle it means it is a right triangle