# SUR 222 Plane Surveying

**HOMEWORK #5 (20 pts) **

**Use engineering computation paper, Excel or a word processed document **

- Compute the corrected (reduced) value of each of the following zenith angles:

Direct |
Reverse |

a. 88 |
271 |

b. 89 |
270 |

c. 83 |
276 |

- Given the following reduced zenith angles and slope distances, compute the horizontal and vertical distances.

Zenith angle |
Slope distance | |

a. |
89 |
234.76’ |

b. |
88 |
250.03’ |

c. |
89 |
1,322.70’ |

- A total station is set at a height of 4.37 feet above a control point which has an elevation of 3910.71 feet. A direct zenith angle reading of 88
^{0}49’ 27” and a reverse zenith angle of 271^{0}10’ 49” and a slope distance of 821.45 feet are observed to point K. The target height at point K is 6.00 feet. What is the elevation at point K? Be sure to correct the zenith angle to correctly do the computations. - A total station is set up on point A. A backsight is observed at point B which has an elevation of 3902.44 feet. The height of the instrument is 4.89 feet and the height of the target is 5.73 feet. A direct zenith angle reading of 90
^{0}02’ 13” and reverse zenith angle reading of 269^{0}58’ 22” and a slope distance of 187.56 feet are observed. What is the elevation at point A? Be sure to correct the zenith angle to correctly do the computations. - A total station is set over a control point at a height of 5.17 feet. The elevation at the control point is 3988.38 feet. The prism is set at a height of 6.00 feet. The following zenith angles and slope distances are measured to the prism pole as it is moved from one point to the next:

Point |
Zenith |
SD |

J |
89 |
287.43’ |

K |
86 |
254.39’ |

L |
92 |
214.87’ |

What are the elevations of points J, K and L?