Current location - Training Enrollment Network - Mathematics courses - Learn math with me every day. For example, 1: Please try to find the value of ∠ A+∠ B+∠ C+∠ D+∠ E in the pentagram. because
Learn math with me every day. For example, 1: Please try to find the value of ∠ A+∠ B+∠ C+∠ D+∠ E in the pentagram. because
Let the intersection of AD and BG be H.

Sum of internal angles of pentagonal BCEFO

∠B+∠C+∠E+∠F+∠BOF=540

∠AHG is the external angle of △HDG.

∠AHG=∠D+∠G

∠BOF is the external angle of △OAH.

∠BOF=∠AHG+∠A

∠BOF=∠A+∠D+∠G

∠A+∠b+∠C+∠E+∠F+∠G =∠b+∠C+∠E+∠F+∠BOF = 540