Make it complex: Having done this, she went away.

♦ Simple Sentence to Complex Sentence: (Having + Verb এর past participle form যুক্ত)
• Structure: Having এর পরিবর্তে When বসে + Subject + had + Verb এর past participle form + বাকী অংশ।

- এ বাক্যে প্রথমেই Having এর পরিবর্তে When বসেছে।
- তারপর Subject - she বসেছে।
- এরপর had + Verb এর past participle form - done বসেছে।
- বাকী অংশ অপরিবর্তিত রয়েছে।

Simple: Having done this, she went away.
Complex: When she had done this she went away.

Source: Advanced Learners Communicative English Grammar & Composition By Chowdhury & Hossain.