Question 1042170
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We have four angles. Let's call them A,B,C,D.

The angles
A = 20
B = 170
are given to us


The other angles (C and D) are unknown. 
We may not know the values, but we know how they're connected. 
They are in a ratio of 2:15, so that means 


C = 2*k
D = 15*k


where k is some positive real number. 


With ANY quadrilateral, the four angles always add to 360 degrees. So


A+B+C+D = 360


Plug in the given values/expressions to get


20+170+2k+15k = 360


Let's solve for k.


20+170+2k+15k = 360
190+17k = 360
17k+190 = 360
17k+190-190 = 360-190 ... Subtract 190 from both sides
17k+0 = 170
17k = 170
17k/17 = 170/17 ... Divide both sides by 17
k = 10


Since k = 10, we can use this to finally determine what C and D are


C = 2*k = 2*10 = 20 degrees
D = 15*k = 15*10 = 150 degrees


So we have these four angles


A = 20 degrees
B = 170 degrees
C = 20 degrees
D = 150 degrees


Notice how

A+B+C+D = 20+170+20+150 = 360 degrees

So that confirms the answer
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