2160
Explanation:
Use the equation (n-2)180
(14-2)180
(12)180
2160
Answer: 29 miles per gallon.
Reasoning: 856 miles/29.4 gallons = 29.1156462585 (rounded to the nearest mile = 29)
Hope this helped!
First you would have to find the third angle in the triangle which you would do by adding 63+61 and subtracting the resulting number from the total degrees in a triangle. From there, you would calculate x and y using the knowledge that angles on a line equal 180.
