Answer:
surface area of the triangular pyramid
=(1/2×9×7.8)+(3×1/2×9×12.3)
=35.1+166.05
=201.15 inch²
The coefficients are the numbers next to a variable (which is X in this case). Therefore, the coefficients here are 4 and 8
Average speed
Average speed between the checkpoints
distance between the checkpoints
divided by
time between the checkpoints.
Distance between the checkpoints =
(mileage at B) minus (mileage at A)
=(208)-(120) = 88 miles .
Time between the checkpoints =
time at - time at A
=(3:00 PM) - (1:00 PM) = 2 hours .
Average speed between the checkpoints =
(88 miles) / (2 hours)
=44 miles per hour .
So angle DBC is equal to 180° - 28° which is 152°
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I hope that helps you out!
Any more questions, please feel free to ask me and I will gladly help you out!!
~Zoey