What is the measure of angle B?

Answer:
m∡B = 120°
Step-by-step explanation:
base angles are equal
adjacent angles are supplementary so:
4x+20 + 3x-15 = 180
7x + 5 = 180
7x = 175
x = 25
∡B = 4(25) + 20
∡B = 120°
Answer:
39.6
Step-by-step explanation:
(3x-15)+(4x+20)+2x=360
9x+5=360
9x=355
*Divide each side by 9*
X=39.4
*SUBSTITUTE X*
3(39.4)-15=103.2
4(39.4)+20=177.6
*ADD THE TOTALS FROM ABOVE*
103.2+177.6= 280.8
360-280.8=79.2
*DIVIDE THE TOTAL BY 2*
79.2/2=39.6
*CHECK*
3(39.4)-15=103.2
4(39.4)+20=177.6
103.2+177.6+39.6+39.6=360 IS CORRECT.
Hope this helps! :)