The area of square lawn is 400m^2 find the side length of the lawn

20m

Explanation:

Area is equal to =l×b

because the square all the sides are equal ..

so since your dealing with the area square both sides

1. it was caused by feudalism

2. charlemagne used christianity as a major cornerstone for his rule. cloisters were built all over the empire to act as centers for the (re)population of the vast european wilderness.

3. the europeans feared the next raid every time chetak

i'm not so sure about #6. but i hope i you with the first 3.