<PRE><B>Question 615874</B>
So supplementary angles means they add up to 180 degrees

as angle B is smaller then we should give it value x.

So we have to find a formula that fits the size of Angle A.

it is three time angle B + 20

so: 3 times x +20

3x+20

So angle A is 3x+20
angle B is x

Adding these together equals 180 so:

3x+20 + x = 180

solve for x:

4x + 20 = 180
4x = 180-20
4x = 160
x = 160/4
x = 40

So angle B is 40 degrees. 

To check. this would mean that angle A is 3 times 40 plus 20 = 120 + 20
                                                             = 140

Add 140 + 40 = 180 !!!</PRE>