Please help me thanks

16.7

Step-by-step explanation:

We can use the Pythagorean theorem, a^2 + b^2 = c^2.

a = 11

c = 20

11^2 + b^2 = 20^2

121 + b^2 = 400

b^2 = 279

b = sqrt(279) = 16.7

isaiah walks 3 miles due north, turns and then 5 miles due east. how far is he from his starting point?

a^2 + b^2 = c^2

let c = distance from starting point.

(3)^2 + (5)^2 = c^2

9 + 25 = c^2

34 = c^2

sqrt{34} = sqrt{c^2}

sqrt{34} = c