(i) 729 can be factorised as follows.

729 = __3 × 3 __× __3 × 3__ × __3 × 3__

∴ √729 = 3 x 3 x 3 = 27

(ii) 400 can be factorised as follow.

400 = __2 x 2__ x __2 x 2__ x __5 x 5__

∴ √400 = 2 x 2 x 5 = 20

(iii) 1764 can be factorised as follows.

1764 = __2 × 2__ × __3 × 3__ × __7 × 7__

∴ √1764 = 2 x 3 x 7 = 42

(iv) 4096 can be factorised as follows.

2 | 4096 |

2 | 2048 |

2 | 1024 |

2 | 512 |

2 | 256 |

2 | 128 |

2 | 65 |

2 | 32 |

2 | 16 |

2 | 8 |

2 | 4 |

2 | 2 |

| 1 |

4096 = __2 × 2__ × __2 × 2__ × __2 × 2__ × __2 × 2__ × __2 × 2__ × 2 × 2

∴ √729 = 2 x 2 x 2 x 2 x 2 x 2 = 64