Gil is reading a book that has 276 pages. on Monday, he read some pages, On Tuesday, he read twice as many pages than Monday. He plans to read 180 pages on Wednesday to finish the book. variable-
equation-
justification-

Variable - let x equal how many pages Gil reads on Monday.

Equation
276= x + 2x + 180

276= 3x+180
X=32

Justify:

He read 2 times the amount of pages making it 2x from the original. He reads 180 to finish the book making the equation done.

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