2015 Java Chapter 4 (Week 04)

From: 2015-09-01 00:00:00 To: 2015-09-28 00:00:00 Now: 2024-11-21 22:22:56 Status: Public

A - 기하: 5각형의 넓이

Time Limit: 1s Memory Limit: 128MB

Submissions: 838 Solved: 554
Description

오각형의 중심으로부터 정점까지의 거리 r을 입력받아 오각형의 넓이를 계산하는 프로그램을 작성하세요.

Write a program that prompts the user to enter the length from the center of a pentagon to a vertex and computes the area of the pentagon, as shown in the following figure.

where r is the length from the center of a pentagon to a vertex. Round up two digits after the decimal point.

 

Input

* Line 1 : 실수 r (0~100)

Output

* Line 1 : pentagon의 넓이 (소수점 둘째 자리로 반올림)

Sample Input
5.5
Sample Output
71.92
Source

JAVA2015 PE4.1