I am a little confused about the question you are trying to ask. It is an isosceles triangle because it has two sides of equal length.
The other angle would be...
180-2(55)=70 degrees
The average speed is the distance divided by the time.
Total distance:
12.8 miles + 17.2 miles = 30 miles
Total time:
noon - 9:00 a.m. = 3 hours
6:00 p.m. - 1:00 p.m. = 5 hours
Total time = 3 hours + 5 hours = 8 hours
average speed = 30 miles / 8 hours = 3.75 miles per hour
Answer:
5:7
5/7
5 to 7
10:14 --> 10x2=20 14x2=28
20:28 --> 20x2=40 28x2=56
40:56