For the first part, the answer is choice B) 360. This applies to any polygon and it doesn't have to be an octagon. The sum of the exterior angles of any polygon is always 360 degrees. This is something you should memorize or have on a reference sheet.
For the second part, the answer is choice C) 142 degrees. We have a parallelogram (specifically a rhombus but that doesn't matter) so the adjacent angles are supplementary. This means they add to 180 degrees. Solving x+38 = 180 leads to x = 142
Step-by-step explanation:
i know this but i don't have time now
Answer:
rate boat = 15 mph
rate current = 5 mph
explanation:
d = r * t
t = d/r
240 / (r_boat + current) = 12 Multiply both sides by r_boat + r_current.
240 = 12(r_boat + current)
240/ (r_boat - current) = 24 Multiply both sides by r_boat - r_current
240 = 24*(r_boat - current)
Since the distances are the same in both equations, you can equate the right side of each.
12 (r_boat + current) = 24(r_boat - current) Divide by 12
r_boat + current = 2 (r_boat - current) Remove the brackets.
r_boat + current = 2*r_boat - 2* current add 2 currents to both sides
r_boat + 3currents = 2*r_boat Subtract r_boat both sides
3 currents = r_boat.
240 = 12*(r_boat + current. Divide by 12
20 = r_boat + current Put 3 currents in for r_boat
20 = 3currents + 1 current Combine
20 = 4 currents Divide by 4
5 = current
The rate of the current = 5 miles / hour
3 currents = r_boat
3*5 = rate_boat
15 = rate of the boat
There are 2880 minutes in two days