Mavzu: masalalarni yechish turlari

Geometrik masala:

Uchburchakning ichki burchaklari 2:3:4 nisbatda bo`lsa, uchburchakning shu burchaklarini toping.
Berilgan masala 7-sinf geometriya kursida uchburchakning ichki burchaklari yig`indisi mavzusini mustahkamlashda bajariladi. Masalani yechishda o`quvchi uchburchakning elementlari nima eknligi, elementlani qanday belgilanishini, ichki burchak, tashqi burchak haqidagi bilimlarga ega bo`lishi ,ichki burchaklarni o`zgartirish kiritish orqali belgilashni kerak.

Teorema: Uchburchakning ichki burchaklari yig`indisi 180⁰ ga teng.

Demak, teorema yordamida masalani bemalol yechish mumkin.
I usul: ( geometrik usul )
Ber: ABC- uchburchak
A=2x, B= 3x, C=4x
Top. kerak: A=? B=? C=?
Yechish:
A+B+C = 180⁰
2x + 3x + 4x =180⁰
9x= 180⁰
x= 180⁰ : 9
x= 20⁰
A=2*20⁰= 40⁰
B= 3*20⁰ = 60⁰
C= 4*20⁰ = 80⁰
Javob : 40⁰ ,60⁰ , 80⁰

II-usul: ( arifmetik usul )
O`quvchi 6-sinf matematika kursida nisbat ,o`rta proporsional miqdor mavzusi bilan tanishgan.Shu mavzudan foydalangan holda berilgan masalani osngina bajarishi mumkin
Demak Uchburchakning burchaklari 2:3:4 nisbatda bo`lsa, bu nisbatlarni qo`shib olamiz.
2+3+4 =9 (jami nisbat )
Endi 1 nisbatga necha gradus to`g`ri kelishini topb olamiz.Bunda uchburchakning ichki burchaklari yig`indisi 180<sup>0</sup> ga tengligidan foydalanib topiladi
180<sup>0</sup> : 9 = 20<sup>0</sup> ( 1 nisbat )
Uchala burchakni topishda 2 nisbat , 3 nisbat , 4 nisbatni osongina hisoblash mumkin.
2*20<sup>0</sup>= 40<sup>0</sup> , 3*20<sup>0</sup> = 60<sup>0</sup> , 4*20<sup>0</sup> = 80<sup>0</sup>
Javob : 40<sup>0</sup> ,60<sup>0</sup> , 80<sup>0</sup>
Teorema: Uchburchakning ishki burchaklari yig`indisi 180⁰ ga teng.
Teorema: Qo`shni burchaklar yig`indisi 180⁰ ga teng
Teorema: Vertikal burchaklar o`zaro teng .
Teorema: Uchburchakning tashqi burchagi o`ziga qo`shni bo`lmagan ihki burchaklar yig`indisiga teng.
Bu teoremalardan foydalanib, 7-sinf o`quvchisi geometriya darsidan olgan bilimlarini Turk geometriyasida berilgan testlarni bemalol ishlashi mumkin.