Odpowiedź:
zad 8
a)
∡ADB = ∡BCD = 40°
∡ABD = 180° - (70° + 40°) = 180° - 110° = 70°
∡CBD = 180° - 70° = 110°
∡BDC = 180° - (110° + 40°) = 180° - 150° = 30°
b)
∡AED = 180° - (110° + 45°) = 180° - 155 = 25°
∡BEF = 180° - (25° + 75°) = 180° - 100° = 80°
∡EDF = 180° - (110° + 20°) = 180° - 130° = 50°
∡DFE = 180° - (75° + 50°) = 180° - 125° = 55°
∡EFB = 180° - (65° + 55°) = 180° - 120° = 60°
∡EBF = 180° - (80° + 60°) = 180° - 140° = 40°