Question

ex 10,11,please,dau coroana

Answer 1

10.
a)AB/4=BC/5=CA/6, aceasta expresie poate fi scrisa si astfel:
(AB+BC+CA)/(4+5+6); Obtinem la numarator suma laturilor ce in matematica se numeste perimetru;
90/15=6, astfel obtinem:
AB/4=6⇒AB=24;
BC/5=6⇒BC=30;
CA/6=6⇒CA=36;
b)Se facem in acelasi mod ca si a)
90/(6+5+7)=5;
AB/6=5⇒AB=30;
BC/5=5⇒BC=25;
CA/7=5⇒CA=35.

11.
Daca vom face unghiuri in jurul unui punct, suma unghiurilor va fi mereu 360grade, adica m(∡A1)+m(∡A2)+m(∡A3)=360;
Rezolvam prin aceeasi metoda ca la 10(la numitor vom obtinem suma unghiurilor=360)
a)360/(10+12+14)=10;
m(∡A1)/10=10⇒m(∡A1)=100grade;
m(∡A2)/12=10⇒m(∡A2)=120grade;
m(∡A3)/14=10⇒m(∡A3)=140grade;
b)360/(13+15+12)=9;
m(∡A1)/13=9⇒m(∡A1)=117grade;
m(∡A2)/15=9⇒m(∡A2)=135grade;
m(∡A3)/12=9⇒m(∡A3)=108grade.