Question

determinati aria discului avand raza egala cu: 5 cm, 2√3 cm, 1,2 cm, 3√2 supra 2 cm

Answer 1

Răspuns:

A = πr²

A = π5² = 25π cm²

A = π(2√3)² = π4•3 = 12π cm²

A = π1,2² = 1,44π cm²

A =

$\pi (\frac{ 3\sqrt{2} }{2} ) {}^{2} = \pi \frac{9 \times 2}{4} = π \frac{18}{4} = 4.5\pi \: cm {}^{2}$