Question

Vă rog ajutaţi-mă!!!!Este pe mâine❤❤❤
cine e bun la mate

Answer 1

1.
din relatie rezulta:
$\frac{CO}{RA}=\frac{ON}{AC}=\frac{CN}{RC}$

si mai rezulta ca:
∡C≡∡R
∡O≡∡A
∡N≡∡C


2.
In ΔABC
DE || BC
⇒T.F.A. ca:

$\frac{AD}{AB}=\frac{AE}{AC}=\frac{DE}{BC}$

$\frac{AD}{AB}=\frac{AE}{AC}$

$(\frac{2,4}{6}=\frac{AE}{12}\\ \\ AE=\frac{12*2,4}{6}=2*2,4=4,8(cm)$ )

$\frac{AD}{AD+DB}=\frac{AE}{AE+EC}$

$\frac{AD}{DB}=\frac{AE}{EC}$

DB=AB-AD=6-2,4=3,6

$\frac{2,4}{3,6}=\frac{4,8}{EC}\\ \\ \rightarrow EC=\frac{4,8*3,6}{2,4}=2*3,6=7,2(cm)$

R: CM=7,2 cm



3.
ΔABC asemesea cu ΔDEF

$\rightarrow \frac{AB}{DE}=\frac{BC}{EF}=\frac{AC}{DF}\\ \\ \frac{AB}{DE}=\frac{BC}{EF}\\ \\ \frac{4}{3}=\frac{8}{EF}\\ \\ EF=\frac{8*3}{4}=2*3=6 (cm)$

R: EF=6 cm