Xochitl can make one trip to the shop and can only bring three boards back. What three board lengths could she choose to make the triangular pen?

.mp4 files, because, video

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:

52 \43 i don't know this i tried

yeah i know the problem you need. i am taking it right now. the answer is step 3

~mickey