A set of four stars form the shape of a rectangle in space. The length of the rectangle is approximately 5,780,000,000 miles, while the width of the rectangle is approximately 4,690,000,000 miles. What is the approximate area of the rectangle?

A.
2.71082 × 10^81 square miles
B.
27.1082 × 10^17 square miles
C.
2.71082 × 10^18 square miles
D.
2.71082 × 101^9 square miles

1 answer

To find the area of a rectangle, you multiply its length by its width. Given:

  • Length = 5,780,000,000 miles
  • Width = 4,690,000,000 miles

Let's convert these numbers into scientific notation for easier multiplication.

  • Length: \( 5,780,000,000 \) miles = \( 5.78 \times 10^9 \) miles
  • Width: \( 4,690,000,000 \) miles = \( 4.69 \times 10^9 \) miles

Now, we can calculate the area:

\[ \text{Area} = \text{Length} \times \text{Width} = (5.78 \times 10^9) \times (4.69 \times 10^9) \]

Using the property of exponents, we multiply the coefficients and add the exponents:

\[ = (5.78 \times 4.69) \times (10^9 \times 10^9) \]

Calculating \( 5.78 \times 4.69 \):

\[ 5.78 \times 4.69 \approx 27.1082 \]

Now for the exponent:

\[ 10^9 \times 10^9 = 10^{9+9} = 10^{18} \]

Putting it all together:

\[ \text{Area} \approx 27.1082 \times 10^{18} \text{ square miles} \]

To express this in standard scientific notation, we can rewrite it:

\[ = 2.71082 \times 10^{19} , \text{square miles} \]

However, since \( 27.1082 \times 10^{18} \) is the result obtained from the multiplication, the answer that fits the format from the options provided would be:

B. \( 27.1082 \times 10^{17} \text{ square miles} \).

Therefore, the correct option is B.