Question

Va rog ajutatima cu aceste exercitii

Answer 1

Variana I ex 1

A dreptunghi = 8*18=144cm²⇒ A patrat=144cm²⇒ l²=144⇒ l=√144 cm
⇒l=12 cm⇒ P patrat = 12*4=48cm

ex4

P = b+l+l
36 = 16+2l⇒ 2l=36-16⇒2l=20⇒ l=20:2⇒l=10 cm
p=36:2=18

A=√18(18-16)(18-10)(18-10) = √18*2*8*8=√36*64=6*8=48cm²

ex5

Diagonala patrat=l√2=6√2
R = raza cerc=digonala patrat/2=6√2:2=3√2

Lungime cerc=2πR = 2π *3√2=6√2 π cm
Arie cerc = R² π = (3√2)²π = 18π  cm²

ex7

B+b = 2L (cand avem cerc inscris in trapez)
b+B=50+50= 100 cm
h = 2R=24*2=48 cm

A trapez = (b+B)*h:2=100 *48:2=2400 cm²
L cerc = 2πR=2π*24=48 π cm
Arie disc = πR² = π 24²=576π cm²