tolong pake rumus kak
[tex]\sf K = 2 \times (p + l)[/tex]
[tex]\sf K =2 \times ((5 \sqrt{3} - 2 \sqrt{15} ) + (20 + \sqrt{15} ))[/tex]
[tex]\sf K = 2 \times (20) + (5 \sqrt{3} ) - ( 2 \sqrt{15} - \sqrt{15} )[/tex]
[tex]\sf K=( 20.2) + (5.2 \sqrt{3} ) - ( 2 \sqrt{15} )[/tex]
[tex]\sf K = \blue{40 + 10 \sqrt{3} - 2 \sqrt{15} \: \: } [/tex]
[tex]\tiny\blue☆[/tex]
