Page 33 - Engineering

‫ﺍﳍﻨﺪﺳﺔ )ﺍﳉﺰء ﺍﻷﻭﻝ(‬ ‫‪٢٠‬‬

‫‪3x + 30 + x − 31 + 3x + 67 = 360°‬‬ ‫اﻟﺤﻞ‪:‬‬
‫‪7x = 360° − 66° = 294°‬‬

‫‪x = 42°.‬‬

‫ﻣﺜﺎل )‪ :(١١‬ﰲ اﻟﺸﻜﻞ اﳌﺮﻓﻖ ‪ n ،m ،l‬ﺛﻼﺛﺔ ﻣﺴﺘﻘﻴﻤﺎت ﺗﻠﺘﻘﻲ ﰲ ﻧﻘﻄﺔ واﺣﺪة‪.‬‬
‫اﺣﺴﺐ ﻗﻴﺎس ‪.xɵ‬‬

‫‪lm‬‬

‫‪140°‬‬

‫‪y°‬‬ ‫‪n‬‬
‫‪x°‬‬
‫‪90°‬‬

‫اﻟﺤﻞ‪ :‬اﳌﺴﺘﻘﻴﻤﺎن ‪ l‬و ‪ n‬ﻣﺘﻌﺎﻣﺪان‪ ،‬إذن‪ .x + y = 90° ،‬ﻟﻜﻦ‬
‫‪ .y = 180° − 140° = 40°‬إذن‪.x = 90° − 40° = 50° ،‬‬

‫ﻣﺜﺎل )‪ :(١٢‬ﰲ اﻟﺸﻜﻞ اﳌﺮﻓﻖ‬

‫‪C‬‬

‫‪D‬‬ ‫‪B‬‬
‫‪E‬‬
‫‪b 30°a‬‬
‫‪a‬‬

‫‪A‬‬
‫‪246°‬‬

‫‪ AC‬ﻣﻨﺼﻒ ﻟﻠﺰاوﻳﺔ ‪ .BAD‬ﻣﺎ ﻗﻴﻤﺔ ‪ b‬؟‬