tolong jawab pake caranya

RUMUS. sn. = n/2. 2a+(n-1)) *b

#jawab no 33)

s35=35/2. (2*1+(35-1))*3
=35/2. (2+34*3)
=35/2. (2+102)
=35/2. 104
=104/2. *35
=52*35
=1.820
jawab nya A