A scale drawing of a lake has a scale of 1cm to 80m. If the actual width of the lake is 1,000m, what is the width of the lake on the scale drawing?

Element a has no reactivity because it has eight valence electrons and cannot gain anymore electron and it wouldn't lose any either

Use pythagorean’s theorem and find the missing side lengths of the two smaller triangles and add them together
13^2 - 12^2 = 5
15^2 - 12^2 = 9
5+9 = 14
14 is the length of each side of the square
14^2 + 14^2 = 19.8
19.8 is the diagonal length of the inside if the square