Răspuns :
Notam trapezul ABCD
consideram ∡A=∡B=50°
∡C=∡D=180°-50°=130°
consideram ∡A=∡B=50°
∡C=∡D=180°-50°=130°
∧ ∧ ∧ ∧
ABCD= tr. isoscel, A ≡ B, C ≡ D
m(∡ A) = m(∡ B) = 50°
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m(∡ C) = m(∡ D) = ?°= x
m(∡ A) + m(∡ B) +m(∡ c) + m(∡ D) = 360°
50°+ 50°+ x°+ x°= 360°
100°+ 2x° = 360°
2x° = 360°- 100°
2x° = 260° I: 2
x = 130°
ABCD= tr. isoscel, A ≡ B, C ≡ D
m(∡ A) = m(∡ B) = 50°
________________________________
m(∡ C) = m(∡ D) = ?°= x
m(∡ A) + m(∡ B) +m(∡ c) + m(∡ D) = 360°
50°+ 50°+ x°+ x°= 360°
100°+ 2x° = 360°
2x° = 360°- 100°
2x° = 260° I: 2
x = 130°