Door is 77 inches high, 35.25 inches wide and 1,75 inches thick how much paint is needed

If you wanted to paint the entire door (even the top and bottom which people don't usually paint)

the surface area is
SA=2(LW+LH+WH)
where L=length, W=width and H=height

given
L=35.25
W=1.75
H=77

SA=2(35.25*1.75+35.25*77+1.75*77)
SA=2(61.6875+2714.25+134.75)
SA=2(2910.6875)
SA=5821.375

you need enough paint to cover 5821.375 square inches of door

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