EXERCISES. I. Read the following words paying attention to the pronuncia­tion:

I. Read the following words paying attention to the pronuncia­tion:

calculation, relation, ratio, angle, triangle, root, roof, balloon, use, cube, deal, meeting.

II. Make up sentences of your own using the words and expres­sions given below:

to be useful to, in engineering work, otherwise, branch of mathematics, branch of physics, to deal with angles, to deal with; triangles, to deal with relations.

III. Answer the following questions:

1. What does trigonometry deal with? 2. In what work is trigonometry especially useful? 3. For what purpose does the carpenter make use of trigonometric relations? 4. What is determined in meteorology by the use of trigonometry?

IV. Translate into Russian:

A branch of mathematics dealing with the relationship between the sides and angles of triangles is called trigonom­etry. It is defined as the branch of mathematics using the fact that numerous problems may be solved by the calculation of unknown parts (sides and angles). The solution of such problems is greatly assisted by the use of the trigonometrical ratios or functions.

V. Translate into English:

С помощью тригонометрии решаются многие измери­тельные задачи на местности, как например, вычисление расстояний между различными пунктами земной поверх­ности (earth surface), вычисление высоты данного предмета, составление карт и т.п. Измерение небольших расстояний производится при помощи стальных измерительных лент (steel measuring tapes). Измерение углов производится при помощи угломерных инструментов (goniometrial instru­ments).

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