Plisss bantu sama caranya​

h = 3 cm

s = 4 cm

s' = 8 mm = 0,8 cm

*perbesaran bayangan = M = s'/s = 0,8/4 = 8/40 = 1/5 kali

* tinggi bayangan =

M = 1/5

h'/h = 1/5

h'/3 = 1/5

5 h' = 3

h' = 3/5

h' = 0,6 cm = 6 mm

* jarak fokus =

1/f = 1/s + 1/s'

1/f = 1/4 + 1/0,8

1/f = (1+5)/4

1/f = 6/4

6f = 4

f = 4/6

f = 2/3 cm

*kekuatan lensa =

1/f = 1(2/3) = 3/2 = 1,5 D

*jari" kelengkungan = R = 2f = 2(2/3) = 4/3 cm