please help me to deal this question~~ thanks~~five touching circles each have radius 1 and their centres are at the vertices of a regular pentagon . What is the radius of the circle through the touching points? A.tan18 B.tan36 C. tan45 D.tan54

来源：学生作业帮助网 编辑：六六作业网 时间：2024/12/23 23:37:39
pleasehelpmetodealthisquestion~~thanks~~fivetouchingcircleseachhaveradius1andtheircentresareatthever

please help me to deal this question~~ thanks~~five touching circles each have radius 1 and their centres are at the vertices of a regular pentagon . What is the radius of the circle through the touching points? A.tan18 B.tan36 C. tan45 D.tan54
please help me to deal this question~~ thanks~~
five touching circles each have radius 1 and their centres are at the vertices of a regular pentagon . What is the radius of the circle through the touching points?
A.tan18 B.tan36 C. tan45 D.tan54 E tan 72

please help me to deal this question~~ thanks~~five touching circles each have radius 1 and their centres are at the vertices of a regular pentagon . What is the radius of the circle through the touching points? A.tan18 B.tan36 C. tan45 D.tan54
应该是 B

tan54
each angle of the pentagon is 108 degrees
then an right angle edge of a right triangle is 1 in length ,and this edge is a circles radius
then tan54=l/1 l=tan54

说汉语，

please to help me please please help me Could you to help me,please.(改错) would you please c______ to help me? please help me to solve the question please help me to this homework! Mike,please help me to carry the Please help me Please help me!Thanks! Help me,please! 英语翻译help me,please! please help me,ok? 英语翻译help me,please! 英语翻译Could you please help me to ( ) the flowers? please help me to answer this question ,ok thanks what is the sonnet? please help me to explain it. 英语翻译Please help me translate it to chinese 数学好的come in to help me ,please!