Tolong beserta cara ..

Lp = 2 x La + (Ka x t)
Lp = 2 x (½ x (20+50) x 16) + (20+34+50+16) x 15
Lp = 2 x 560 + 120 x 15
Lp = 1120 + 1800
Lp = 2920 cm²
*maaf klo salah