We assume the base is 12 in × 20 in, so its diagonal has length
... √(12² +20²) = √(144 +400) = √544 = 4√34 . . . inches
Then the tangent of the angle of interest is the ratio of the box height to the base diagonal:
... tan(α) = (7 in)/(4√34 in) ≈ 0.300123
The angle will be the arctangent of this value,
... α = arctan(7/√544) ≈ 0.291569 radians
10. He will need 11,4 minutes to get to sea level. To get to 30 he'll need 6 minutes.
11. He'll be able to cut 4 complete pieces.
T chart
substitute various x values, and find the corresponding f(x) or y value
draw it all up in a t-chart, then plot each corresponding coordinate point.
complete the trend if you see one
