Page 105 - Bangladesh_classwiz_BOOK2018_rev_Neat

9.3 wewfbœ PZzf©v‡M w·KvYwgwZK AbycvZmg~‡ni wPý wbY©q

Kv‡Z©mxq ¯’vbv¼ e¨e¯’vq `yBwU Aÿ ( Aÿ I Aÿ) †iLv Øviv PviwU PZyf©vM wba©vwiZ n‡q _v‡K| GB PviwU
PZzf©v‡Mi cÖwZwU‡Z w·KvYwgwZK AbycvZ mg~‡ni wPý wfbœ wfbœ iKg nq| cÖ_g PZzf©vM w·KvYwgwZK Abycv‡Zi

Rb¨ 0° †_‡K 90° wb‡`©k K‡i| wØZxq PZzf©vM 91° †_‡K 180°, Z…Zxq PZzf©vM 181° †_‡K 270° Ges PZz_©
PZzf©vM 271° †_‡K 360° wb‡`©k K‡i| ‡Kv‡bv PZzf©v‡M ‡Kv‡bv GKwU w·KvYwgwZK Abycv‡Zi wPý abvZ¥K bv
FYvZ¥K Zv †evSvi Rb¨ H PZzf©v‡Mi †KvY wb‡q wbixÿv Ki‡Z nq| aiv hvK, wØZxq PZzf©v‡M Gi wPý †Kgb
Zv †ei Ki‡Z n‡e| GRb¨ 91° †_‡K 180° Gi g‡a¨ ‡Kv‡bv gvb wb‡Z n‡e| G‡ÿ‡Î 120° wb‡q wb‡Pi w¯Œ‡b
†`Lv‡bv n‡jv-

Abyiƒcfv‡e wØZxq PZzf©v‡M Gi wPý †ei Kivi Rb¨ wb‡Pi w¯Œ‡bi g‡Zv K‡i 120° Gi gvb
†`Lv‡bv n‡jv-

GB `yBwU D`vniY †_‡K GwU ¯úó †h wØZxq PZzf©v‡M Gi wPý abvZ¡K wKš‘ Gi wPý FYvZ¥K|
Abyiƒcfv‡e, †h‡Kv‡bv PZzf©v‡M w·KvYwgwZK Abycv‡Zi wPý †ei Kiv hvq|

9.4 w·KvYwgwZK AbycvZhy³ ivwki gvb wbY©q

w·KvYwgwZK AbycvZhy³ ivwki gvb wbY©q Kivi Rb¨ cÖ_‡g J e¨envi K‡i Gi GKwU gvb †g‡gvwi‡Z msiÿY

Ki‡Z n‡e| Gi †h‡Kv‡bv gvb wb‡qB K¨vjKz‡jkb Kiv hv‡e, Z‡e jÿ¨ ivL‡Z n‡e †hb gvbwUi Rb¨ ivwki gvb
AmsÁvwqZ bv nq| †hgb- 90° Gi gvb AmsÁvwqZ ZvB ivwk‡Z _vK‡j 90° e¨envi Kiv hv‡e
bv| Avevi 90° Gi gvb 0 ZvB ivwk‡Z ( 1 ) _vK‡jI Gi gvb 90° †bIqv hv‡e bv| ZvB

†ekxi fvM †ÿ‡Î = 35° e¨envi Kiv DËg|
Gi gvb wn‡m‡e 35 †g‡gvwi‡Z msiÿY Kivi ci †h ivwkwUi gvb wbY©q Ki‡Z n‡e Zv K¨vjKz‡jU‡i UvBc Ki‡Z
1 1 1
n‡e, ivwk‡Z , , _vK‡j Zv‡`i cwie‡Z© h_vµ‡g , , UvBc Ki‡Z

n‡e| Gici = evUb Pvc‡j ivwkwUi gvb cvIqv hv‡e|
1 1
D`vniY¯^iƒc aiv hvK, + Gi gvb †ei Kivi Rb¨ cÖ_‡g J e¨envi K‡i 35 †K
2
2
1+ 1+
‡g‡gvwi‡Z msiÿY Ki‡Z n‡e| Gici ivwkwU wb‡Pi g‡Zv K‡i K¨vjKz‡jU‡i UvBc Ki‡Z n‡e| Gici =evUb
Pvc‡j wb‡Pi wØZxq w¯Œ‡bi g‡Zv djvdj cÖ`wk©Z n‡e|

wØZxq w¯Œb n‡Z †`Lv hv‡”Q ivwkwUi gvb 1.

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