निम्नलिखित में से कौन सा पैरामीटर एक टोटल स्टेशन (total station) मौलिक रूप से सीधे मापने में असमर्थ होता है, जिसके बजाय अन्य प्रेक्षित मानों से गणितीय गणना की आवश्यकता होती है?

In survey work using a total station with reflector measurements, which of the following sequence of temporary adjustments must be performed at a station?

While carrying out a total station survey on one bank of a 250 m wide river, it is necessary to plot electric transmission posts on the opposite bank. No provision exists for crossing the river and the posts are inaccessible. In which mode should the survey work be done?