Question

A sphere has an area equal to 4800 cm2. Considering π = 3, what is the measure of its radius? * 15 cm 10 cm 144 cm 12 cm 20 cm​

Answer 1

We are given –

$\sf \begin{cases} \sf A_{\circ} = 4\: 800\: cm^2 \\ \sf \pi = 3 \\ \sf r = \:?\: cm\end{cases}$

• A sphere is a three-dimensional object that results from the rotation of a circle around its diameter.The spherical surface area is given by–

• $\pink{\bf\boxed{ \bf{A = 4 \pi \cdot r^2}}}$

Just use the formulas for the sphere's area to determine the radius.

$\qquad$ $\red{\twoheadrightarrow\bf A_{\bigcirc} = 4 \pi \cdot r^2}$

$\qquad$ $\twoheadrightarrow\sf 4\:800 = 4 \cdot 3 \cdot r^2$

$\qquad$ $\twoheadrightarrow\sf 4\:800 = 12 \cdot r^2$

$\qquad$ $\twoheadrightarrow\sf r^2 = \dfrac{4\:800}{12}$

$\qquad$ $\twoheadrightarrow\sf r^2 = 400$

$\qquad$ $\twoheadrightarrow\sf r = \sqrt{400}$

$\qquad$ $\red{\twoheadrightarrow\bf r = 20\: cm}$

Henceforth, the radius of the sphere measures $\bf = 20\: cm$.

Answer 2

Answer:

20 cm

Step-by-step explanation:

Use the formula

A=4πr^2

Solving for radius

$r = 1/2 \sqrt{A/\pi } = 1/2 \sqrt{4800/\pi }$ ≈ 19.5441