Page 115 - Engineering

‫ﺍﳍﻨﺪﺳﺔ )ﺍﳉﺰء ﺍﻷﻭﻝ(‬ ‫‪١٠٢‬‬

‫‪W = 1×3×4 = 6‬‬
‫‪2‬‬

‫إذن‪. X +Y = 9 + 8 = 25 = Z ،‬‬

‫‪22‬‬

‫)‪ [AMC8 2000] (٣٤‬ﰲ اﻟﺸﻜﻞ اﳌﺮﻓﻖ ‪ .A = 20°‬ﻣﺎ ﻗﻴﺎس ‪ B + D‬؟‬

‫‪B‬‬

‫‪G‬‬ ‫‪C‬‬

‫‪A‬‬ ‫‪20°‬‬ ‫‪x°‬‬
‫‪x°‬‬

‫‪F‬‬

‫)د( ‪80°‬‬ ‫‪E‬‬ ‫‪D‬‬ ‫)أ( ‪48°‬‬

‫)ج( ‪70°‬‬ ‫)ب( ‪60°‬‬

‫اﻟﺤﻞ‪ :‬اﻹﺟﺎﺑﺔ ﻫﻲ )د(‪ .2x = 180° − 20° = 160° :‬إذن ‪ .x = 80°‬اﻵن‬

‫‪ x = B + D‬ﻷ‪‬ﺎ زاوﻳﺔ ﺧﺎرﺟﺔ ﻋﻦ اﳌﺜﻠﺚ ‪ .△FBD‬إذن‪.B + D = 80° ،‬‬

‫)‪ [AMC8 1997] (٣٥‬ﰲ اﻟﺸﻜﻞ اﳌﺮﻓﻖ ‪ ABC‬ﻣﺴﺘﻘﻴﻢ و ‪ .ɵ3 = ɵ4‬ﻣﺎ ﻗﻴﺎس ‪ ɵ4‬؟‬

‫‪E‬‬

‫‪40°‬‬
‫‪D‬‬
‫‪3‬‬

‫‪70° 4‬‬
‫‪A BC‬‬