What is biosphere? what are the main elements of biosphere ?​

What is the approximate circumference of the circle shown below? 12.2 cm

Sarah is making a scale drawing of a painting that is 48inches wide by 120 inches high her paper is 12 inches wide and 24 inches tall she decides to use a scale 1 inches equals 4 inches is this a reasonable scale

1. crust 1 the metallic layer at the earth's center 2. inner core 3 the firm layer between the crust and the asthenosphere 3. lower mantle 2 the layer surrounding the inner core 4. asthenosphere 4 the semi-solid layer between the top layer and the upper mantle 5. upper mantle 5 the layer between the asthenosphere and lower mantle 6. top layer 6 the earth's outermost layer 7. outer core 7 the hottest part of the mantle