Why were early people in North America able to build complex cultures? a.
They had learned how to farm.
b.
They had learned how to start fires.
c.
They had advanced weapons.
d.
They had a written language.

adopted the practice of proskynesis, a persian court custom that involved bowing down and kissing the hand of others, depending on their rank.

the perimeter of a triangle is 69 cm. side a is 5 cm shorter than side b. side c is twice as long as side a. find the length of each side. i need to know how to do it in 2 equations.  

equations:

a = b-5

c = 2a

a + b + c = 69