perhatikan gambar berikut. jika besar -BOC=108° Dan besar -AOD=80° maka tentukan: a.besar -BEC, b.besar -AED, c.besar -AEB, d.besar -DEC
Matematika
azizah472
Pertanyaan
perhatikan gambar berikut. jika besar -BOC=108° Dan besar -AOD=80° maka tentukan:
a.besar -BEC,
b.besar -AED,
c.besar -AEB,
d.besar -DEC
a.besar -BEC,
b.besar -AED,
c.besar -AEB,
d.besar -DEC
1 Jawaban
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1. Jawaban whongaliem
∠ BOC + ∠ AOD + ∠ AOB + ∠ DOC = 360°
108° + 80° + ∠ AOB + ∠ DOC = 360°
188° + ∠ AOB + ∠ DOC = 360°
∠ AOB + ∠ DOC = 360° - 188°
∠ AOB + ∠ DOC = 172°
a) ∠ BEC = 1/2 (∠ BOC + ∠ AOD) .... (∠ BEC = sudut kll dalam)
= 1/2 (108° + 80°)
= 1/2 (188°)
= 94°
b) ∠ AED = ∠ BEC ... (saling bertolak belakang)
= 94°
c) ∠ AEB = 1/2 (∠ AOB + ∠DOC )
= 1/2 (172°)
= 86°
d) ∠ DEC = ∠ AEB
= 86°