tolong bantu menjawab pertanyaan ini

d = 17 cm
PGSPL = 15 cm
Rn = 3 cm
Rm = x
(Rm - Rn) = [tex] \sqrt{d^{2} - PGSPL^{2} } [/tex]
(x - 3) = [tex] \sqrt{17^{2} - 15^{2} } [/tex]
x - 3 = [tex] \sqrt{289 - 225} [/tex]
x - 3 = [tex] \sqrt{64} [/tex]
x - 3 = 8
x = 8 + 3
x = 11
Rm = 11 cm