math
posted by badatmath on .
A longdistance runner runs 3 miles south and then 7 miles east. How far is the runner from the starting point
A) 8.616 mi
B) 10 mi
C) 7.616 mi
D) 4.472 mi
I think it is eaither A or C but not sure

Using the Pythagorean Theorem, I found the distance to be 7.616 miles.
a^2 + b^2 = c^2
3^2 + 7^2 = c^2
9 + 49 = 58
square root of 58 = 7.616 
simple case of using Pythagoras
d^2 = 3^2 + 7^2
d^2 = 58
d = √58 = 7.616 