已知：如图是七角星形,求角A+角B+角C+角D+角E+角F+角G=?

已知：如图是七角星形,求角A+角B+角C+角D+角E+角F+角G=?
已知：如图是七角星形,求角A+角B+角C+角D+角E+角F+角G=?

已知：如图是七角星形,求角A+角B+角C+角D+角E+角F+角G=?

如图,
∠B+∠F=∠1,
∠C+∠G=∠2,
∠A+∠E=∠3,
∠1+∠2=∠4,
∴∠A+∠B+∠C+∠D+∠E+∠F+∠G
=∠1+∠2+∠3+∠D
=∠4+∠3+∠D
=180°