Question

Calculati lungimea cercului cu raza de:
a)10cm b)6 intregi si 2 pe cinci c)2,(3) d)2 pe ''pi''

Va rog frumos ajutatima

Answer 1

Răspuns:

Explicație pas cu pas:

$\displaystyle L cerc = 2\pi \times r$

a) r = 10

$\displaystyle L cerc = 2\pi \times r = 2\pi \times 10 = 20\pi$

b)

$\displaystyle r = 6 \frac{2}{5} = \frac{6 \times 5+2}{5} = \frac{32}{5}$

$\displaystyle L cerc = 2 \pi \times r = 2 \pi \times \frac{32}{5} =\frac{64}{5} \pi =12,8 \pi$

c)

$\displaystyle r = 2,( 3) = 2 \frac{3}{9} = \frac{2 \times9 +3}{9} = \frac{21}{9} ^{(3} =\frac{7}{3}$

$\displaystyle L cerc= 2 \pi \times r = 2 \pi \times \frac{7}{3} = \frac{14}{3} \pi = 4,(6) \pi$

   

d)

$\displaystyle r = \frac{2}{\pi }$

$\displaystyle L cerc= 2\pi \times r = 2 \pi \times \frac{2}{\pi } = \frac{4\pi }{\pi } ^{(\pi } = 4$