First you figure out that the ratio 7:4 is 1.75
Then you do this problem 28 divided by 1.75=16
And 28:16 is the same as 7:4
Now all you do is add 28+16=44
In the figure below
1) Using the theorem of similar triangles (ΔBXY and ΔBAC),

Where

Thus,

thus, BC = 7.5
2) BX = 9, BA = 15, BY = 15, YC = y
In the above diagram,

Thus, from the theorem of similar triangles,

solving for y, we have

thus, YC = 10.
I gotchuuuu
Ok so angle ABC we’re gonna call it X
Angle BCD is 2X
The trick is the sum of angles of a pentagon is 540 degrees.
90 + 115 + 125 + 2X + X = 540
3X = 540-330
X = 70
SoOoOoOoOooooo
Angle BCD is 140 degrees !!
5 boxes of pens
4 boxes of pencils