Plz help I will give brainiest

Hi there!

The correct answer to this question is: 15.21 ft^2

Step-by-step explanation:

The area of square is base^2 therefore given the measurement of the base we can plug this in into the equation and get (3.9)^2 = 15.21

explanation:

infrared radiation has wavelength in the range between 700 nm and 1 mm. lets' convert these values into scientific notation, keeping in mind that:

let's start from the lower value, we have:

(we moved the dot two places to the left, so we increased the exponent by 2 units, from -9 to -7)

the higher value is:

so, the range of wavelength of infrared radiation is:

b