Выберите правильное название сочинения Р. К. Щедрина

dj-так называют человека.

правильно красавчик)

mark and he are thirteen years old.and they are very sportly. they often go to the gym - at least three times a week. mark does exercises to make his arms strong. he can't walk because of a car accident, so he goes everywhere in wheelchair. but it doesn't stop him doing the things that boys his age want to do.

s = pi*r^2

r=r/2  

подставим

s=pi*(r/2)^2

s=(pi*r^2)/4