Question

URGENT!!(2 probleme multe puncte deci va rog :( )
1.In triunghiul ABC,se duce MN || BC,M ∈ (AB),N ∈(AC).
a)AN=? daca MB=6,AB=9,NC=4
b)NC=? daca AB=16,MB=12,AN=3

2.In trapezul ABCD,AB || CD.
O este intersectia diagonalelor.
Aflati OD daca AO=6,CO=9,BO=4

Answer 1

1)a) AB/MB=AC/NC
       9/6=AC/4
   AC=9X4/6=6
AN=AC-NC=6-4=2       AN=2
b)AM=AB-MB=16-12=4
AB/AM=AC/AN
16/4=AC/3
AC=16X3/4
AC=12
NC=AC-AN=12-3=9
NC=9

2)AO/OC=OB/OD
6/9=4/OD     OD=9X4/6=6 OD=6

Answer 2

1 a) AM = 9 - 6 = 3
AM/MB = AN/NC
3/6 = AN/4
AN = 3 x 4 / 6 = 12/6 = 2

b) AM = 16 - 12 = 4
AM/MB = AN/NC
4/12 = 3/NC
NC = 12 x 3 / 4 = 36 / 4 = 9

2. CO/OA = DO/OB
9/6 = DO/4
DO = 9 x 4 / 6 = 36/6 = 6