Hannarita/다각형의 넓이 구하는 함수 만들기 완료

* 1차 다각형넓이구하기

* 1.함수명 변경 2.숫자판별을 함수가 아닌 개별 함수내의 조건으로 재설정 3.let pi > const pi 4.return 오류 수정

* 다각형 넓이 (#29)

* index of polygonSize

* Full index of html and get area of circle, square, trapezoid, cylinder

* restart

* add sizeCircle function

* add function sizeSquare, add testcode

* add function sizeTrapezoid, add test code

* add function sizeSylinder, add distinguish test code, add test code

* modify by referring to feedback, add function getArea, add function printExecutionSequence

* Revise var to const, Change variable name arr -> ExecutionSequenceArray, and Revise PrintExecutionSequence function(revise forEach method to use arrow function),

* revise isNum function to use 'for' statement and add typenumberfunction for isNum function

* modifiy function sizeCircle to CalcCircleWidth and change inner contents

* Modify sizeSquare function to CalcRectWidth and change inner contents

* Modify sizeTrapezoid function to calcTrapezoidWidth function and revise inner contents

* Modify sizeSylinder functino to calcSylinderWidth function and revise inner context

* Modify getArea function to check Number of arguments

* Revise little bugs,(add return to calcSylinderWidth, change some upperCase to lowerCase

* step2-1 (YM)

* step2-1 ym

step2-2 YM & TUNA