Please give me questions about finding the circumference of a circle

answer: 4  

the square root of 16 is 4. it is a very simple mathematic concept. a square root when a number multiplied by itself will result in a number. here, the number 16 comes when 4 is multiplied by 4. hence the square root of 16 is 4. you can always figure out a square root by the inverse operation of squaring.  

can someone me: the midsegment through the legs of an isosceles triangle is 4 in. find the sides of the triangle if its perimeter is 20 in. ,   and point g is the centroid of the right △abc with hypotenuse ab=18 in. find cg.