Bisa tolong Bantu jawab ? Besok di kumpul

Bisa tolong Bantu jawab ? Besok di kumpul

1). $l^{2} = p^{2} - (R-r )^{2}$
$12^{2} = p^{2} - (7-2)^{2}$
$144 +25 = p^{2}$
$p = sqrt{169}$
$p = 13 cm$
2). $l^{2} = p^{2} - (R-r )^{2}$
$l^{2} = 25^{2} - (13-6 )^{2}$
$l^{2} = 625 - 49$
$l = 24 cm$
3). $l^{2} = p^{2} - (R+r )^{2}$
$l^{2} = 10^{2} - (4+2 )^{2}$
$l^{2} = 100 - 36$
$l^{2} = 64$
$l = 8 cm$ maaf no.3 kurang jelas menurutku