The measure of angle m<EBF is 56degrees given that angle EBC=3r+10 and angle ABE=2r-20
The point where two lines meet is known as an angle.
Find the diagram attached
The sum of angle EBC and ABE is supplementary, hence:
m<EBC + m<ABE = 180degree
3r+10+2r-20 = 180
3r+2r - 10 = 180
5r = 180 + 10
5r = 190
r = 190/5
r = 38degrees
Next is to get the angle m<EBF.
From the given diagram, the m<ABE = m<EBF
m<EBF = 2r - 20
m<EBF = 2(38)-20
m<EBF = 76 - 20
m<EBF = 56degrees
Hence the measure of angle m<EBF is 56degrees