Below is an instruction that describes a task. Write a response that appropriately completes the request in Swahili. Please answer in Swahili.

### Instruction:
 Roland anahitaji urefu wa uzi ili kukamilisha mazoezi. Ana uzi wenye urefu wa sentimita 12 lakini mwalimu wake anasema anahitaji theluthi tatu zaidi ya alivyonayo. Urefu jumla unaohitajika ni upi?


### Response:
 Inahitajika theluthi tatu zaidi ya sentimita 12 ambayo ni 12cm*(3/4) = <<12*(3/4)=9>>9cm
Urefu jumla unaohitajika ni 12cm+9cm = <<12+9=21>>21cm