What steps are being taken to address the environmental challenges brought on by industrialization in europe? describe two examples of renewable forms of energy

Some of the biggest reforms have been in the usage of renewable energy, such as the solar energy, and the wind energy. Both types, the solar and wind energy, and for free, do little to no damage to the environment, and gradually in the past few decades their usage have been steadily increasing.

begins a massive airlift of food, water, and medicine to the citizens of the besieged city

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