+ 4Sana: 201 y. Mavzu: to’G’ri chiziq. Kesma darsning maqsadi

4. Yangi mavzuni mustahkamlash:

136. Ixtiyoriy burchak chizing va uni transportir yordamida o’lchang.

137. Ixtiyoriy kesishuvchi ikki to’g’ri chiziq kesishidan hosil bo’lgan (1, 2, 3, 4) burchaklarni o’lchang va yozing (75-rasm). Natijaga e’tibor bering. Bunda 1=3, 2=4, 1+2=2+3=3+4=4+1=180^o va 1+2+3+4=360^o bo’lishi kerak. Aks holda o’lchashni aniq bajarmagan bo’lasiz.

138. Biror yoyiq burchakni chizing va uning uchidan chiquvchi nur hosil qilgan ikkala burchakni o’lchang. Agar o’lchangan burchaklar yig’indisi 180^o ga teng bo’lmasa, noto’g’ri o’lchagan bo’lasiz (76-rasm).

139. Transportir yordamida 22^o, 130^o li burchaklarni yasang.

140. 200^o li burchakni transportir yordamida yasash mumkinmi? 350^o li burchakni-chi?

141. Biror uchburchak chizing, uning uchala burchagini o’lchang. So’ngra burchaklarning yig’indisini toping. Agar uchala burchak yig’indisi 180^o ga teng chiqmasa, o’lchashda yanglishgan bo’lasiz.