A straight line is 180 degrees and 144 is on a straight line. So, 180-144 which is 36. So, now we know 2 angles and the Degrees of a triangle is 180 degrees.
36+76+d= 180 D= 68
I assume that you meant RS and ST are segments of RT. If that is true then:
RS+ST=RT, using the values for these given...
8y+4+4y+8=36 combine like terms on left side
12y+12=36 subtract 12 from both sides
12y=24 divide both sides by 12
y=2
Students in 2014 = (100% + 33%) × 2,300
students in 2014 = 133% × 2,300
students in 2014 = 133/100 × 2,300
students in 2014 = 3,059
There are 3,059 students in 2014
