Please answer it now in two minutes

3.6

Step-by-step explanation:

Pythagorean theorem:

a^2 + b^2 = c^2

(6 km)^2 + b^2 = (7 km)^2

36 + b^2 = 49

b^2 = 13

b = sqrt(13)

b = 3.6

3.6 km

step-by-step explanation:

1. practice, practice & more practice

2. review errors

3. master the key concepts

do not try to memorise the processes.

4. understand your doubts.

5. create a distraction free study environment

6. create a mathematical dictionary

7. apply maths to real world problems.

so far i think you have the right thing going for you just remember soh cah toh

step-by-step explanation:

sine over hypotenuse

cosine   equals adjacent

tangent over hypotenuse