http://www.ck12.org Chapter 9. Circles
mAB̂=m^6 ACB. So,mAB̂= 102 ◦.
mADB̂= 360 ◦−mAB̂= 360 ◦− 102 ◦= 258 ◦Example B
Find the measures of the minor arcs in
⊙
A.EBis a diameter.BecauseEBis a diameter,m^6 EAB= 180 ◦. Each arc has the same measure as its corresponding central angle.
mBF̂=m^6 FAB= 60 ◦
mEF̂=m^6 EAF= 120 ◦→ 180 ◦− 60 ◦
mED̂=m^6 EAD= 38 ◦→ 180 ◦− 90 ◦− 52 ◦
mDĈ=m^6 DAC= 90 ◦
mBĈ=m^6 BAC= 52 ◦Example C
Find the measures of the indicated arcs in
⊙
A.EBis a diameter.a)mF ED̂
b)mCDF̂
c)mDFĈ
Use the Arc Addition Postulate.