Page 32 - Engineering

‫ﺍﳌﺴﺘﻘﻴﻤﺎﺕ ﻭﺍﻟﺰﻭﺍﻳﺎ ‪١٩‬‬

‫ﻣﺜﺎل )‪ :(٨‬ﰲ اﻟﺸﻜﻞ اﳌﺮﻓﻖ‪ ،‬ﺟﺪ ﻗﻴﺎس ‪.xɵ‬‬

‫‪x°‬‬
‫‪42°‬‬

‫‪92°‬‬

‫اﻟﺤﻞ‪) x° + 42° + 92° = 360° :‬ﳌﺎذا؟(‪ .‬إذن‪،‬‬
‫‪.x ° = 360° − 134° = 226°‬‬

‫ﻣﺜﺎل )‪ :(٩‬ﰲ اﻟﺸﻜﻞ اﳌﺮﻓﻖ‪ ،‬ﺟﺪ ﻗﻴﺎس ‪.dɵ‬‬

‫‪a°‬‬ ‫‪b° c°‬‬ ‫‪d°‬‬
‫‪120°‬‬

‫اﻟﺤﻞ‪ aɵ = 120° :‬ﺑﺎﻟﺘﻘﺎﺑﻞ ﺑﺎﻟﺮأس‪ ɵb = 120° .‬ﺗﻨﺎﻇﺮ ‪.aɵ‬‬
‫‪ ɵc = 180° − b° = 180° − 120° = 60°‬ﻷن ‪ ɵb + ɵc‬زاوﻳﺔ ﻣﺴﺘﻘﻴﻤﺔ‪.‬‬

‫إذن‪ dɵ = ɵc = 60° ،‬ﺑﺎﻟﺘﻨﺎﻇﺮ‪.‬‬

‫ﻣﺜﺎل )‪ :(١٠‬ﰲ اﻟﺸﻜﻞ اﳌﺮﻓﻖ‪ ،‬ﺟﺪ ﻗﻴﻤﺔ ‪.x‬‬

‫‪(x − 31)°‬‬ ‫‪67° 3x °‬‬
‫‪(3x + 30)°‬‬