(1) ∠x を求めなさい.
50° A x B 43° C 124° D E F |
(2) ∠x を求めなさい.
70° A 30° B x C 130° D E F |
(3) ∠x を求めなさい.
60° A x B 37° C 124° D E |
(4) ∠x を求めなさい.
56° 41° x 28° |
(1) ∠x を求めなさい.
50° A x B 43° C 124° D E F ∠CFB = 50 + 43 = 93 ∠BDCは△BDFの頂点Dにおける外角だから∠BDC = ∠B+∠CFB ∠B = ∠x = ∠BDC − ∠CFB = 31 |
(2) ∠x を求めなさい.
70° A 30° B x C 130° D E F よって,∠DFB = ∠BDC − ∠B = 130 − 30 = 100 ∠DFBは△AFCの頂点Fにおける外角だから∠DFB = ∠A+∠C ∠DFB = ∠A + ∠x = 100 よって,∠x = 30 |
(3) ∠x を求めなさい.
60° A x B 37° C 124° D E よって,∠CED = ∠BDC − ∠C = 124 − 37 = 87 ∠CEDは△ABEの頂点Eにおける外角だから∠CED = ∠A+∠B ∠CED = ∠A + ∠x = 87 よって,∠x = 27 |
(4) ∠x を求めなさい.
56° 41° x 28° 対頂角 = 180−(∠x+41) = 180−(56+28) ∠x = 43 |