Post-Reading Activity

Ex.5. Answer the following questions.

1. What is a triangle? (Give the definition of a triangle)

2. How many types of triangles there exist?

3. According to what can they be classified?

4. What triangle is called equilateral?

5. How many sides are equal in length in an isosceles triangle?

6. In what triangle are all three angles different in measure?

7. Does a right triangle contain three right angles?

8. What triangles are referred to as oblique?

9. Can any triangle be called acute-angled?

10. How do we call a triangle with an interior angle of 180°?

11. Do triangles have any properties which are common to all types?

12. How can the area and the perimeter of a triangle be calculated?

Ex.6. Fill in the blanks with the words from the box. Mind there are two extra words.

a. equilateral, e. right, i. hypotenuse,

b. isosceles, f. legs, j. Pythagorean theorem,

c. interior, g. oblique, k. degenerate,

d. scalene, h. triangle, l. acute.

1. A … is one of the basic shapes of geometry.

2. In a … triangle all sides are unequal.

3. In an … triangle two sides are equal in length.

4. A … triangle has one of its interior angles measuring 90°.

5. The other two sides are called the … of the triangle.

6. Right triangles obey the … .

7. In an … triangle all sides have the same length.

8. A triangle with an interior angle of 180 is… .

9. Triangles that do not have an angle that measures 90° are called … triangles.

10. The side opposite to the right angle is the … .

Ex.7. Find out whether the statements are True or False according to the information in the text. Use the introductory phrases:

I think, it’s right. I’m afraid, it is wrong.

Quite so. Absolutely correct. I don’t quite agree to it.

I quite agree to it. On the contrary. Far from it.

1. A triangle is a polygon with three vertices and three edges which are not line segments.

2. Triangles can be classified according to the relative lengths of their sides and according to their external angles.

3. An equilateral triangle is a regular polygon with all angles measuring 60°.

4. An isosceles triangle has three angles of the same measure.

5. In a scalene triangle its three angles are all different in measure.

6. Triangles having an angle that measures 90° are called oblique triangles.

7. The longest side of the right triangle is called the hypotenuse.

8. A triangle having one angle that measures more than 90° is an acute triangle.

9. A triangle with an exterior angle of 180° is degenerate.

10. Triangles have only one distinctive property which is common to certain types.

11. The interior angles of a triangle always add up to 360°.

12. The perimeter of a triangle is equal to the sum of its three sides.

Ex.8. Match the English words and word combinations with their Russian equivalents.

regular polygon; to construct an equilateral triangle; to define an isosceles triangle; different in measure; to find a scalene triangle; to measure in degrees; the right angle; an interior angle; the legs of the right triangle; to construct an oblique triangle; distinctive properties; height and base of a triangle

отличительные свойства; прямой угол; высота и основание треугольника; внутренний угол; измерять в градусах; найти неравносторонний треугольник; строить равносторонний треугольник; построить косоугольный треугольник; катеты прямоугольного треугольника; различные по величине; правильный многоугольник; определять равнобедренный треугольник

Ex.9. Complete the grid with the nouns from the text.

1				10
2
3
		4
		5
		6
		7
			8
	9

Across

1. the side opposite to the right angle;

2. area or a figure having four equal sides and right angles;

3. corner points of any figure or angle;

4. form or figure;

5. a measurement of distance or dimension;

6. the unit of angle;

7. a plane figure that is bounded by a closed path or circuit;

8. the measurement of vertical distance;

9. the other name for ‘catheti’;

Down

10. figures that have three sides and three angles.

Ex.10. Match the left and the right parts of the sentences.

The interior angles of a triangle A triangle is a polygon with In a scalene triangle A right-angled triangle has The three angles of a scalene triangle A triangle with an interior angle of 180° The exterior angles of a triangle In an equilateral triangle Angles and sides in triangles are related by In an isosceles triangle

are all different in measure is degenerate two sides are equal in length always add up to 360° the cosine rule and sine rule all sides have the same length always add up to 180° three vertices and three edges all sides are unequal one of its interior angles measuring 90°

Ex.11. Let’s revise Perfect Tenses. Complete the sentences using the words from the box.

already before ever for just by since so still yet never

1. Have you … dreamt of going to London?

2. I haven’t worked out how to set the timer on the video ….

3. My dad’s lived in the same house … he was born.

4. The film’s only been on … a couple of minutes.

5. Kate has passed three exams out of five … far.

6. He will have translated the text … 3 o’clock tomorrow.

7. He’s only … got home.

8. It’s eleven o’clock and he … hasn’t come home. Where could he be?

9. I’ve … met Ann …. What’s she like?

10. He has … finished doing his homework.

Ex.12. Transform the sentences from Perfect Active into Perfect Passive.

1. She has just typed her report for the conference. 2. The teacher told us that she had checked all the tests. 3. The student will have written his degree work by May. 4. They have learnt a lot of new English words. 5. He hasn’t found the answer yet. 6. I’ve just received my exam results. 7. By the end of the conference, the participants had discussed a number of important questions concerning the problem. 8. They will have read two books on topology by the end of the month. 9. We had planned the meeting months in advance, but we still had problems. 10. I had discussed the plan of my work with my science adviser before the end of the class.

Ex.13. Find mistakes in the following sentences. Mind the use of Perfect Tenses in the Active and Passive Voice.

1. They finished their experiment by 5 o’clock yesterday.

2. The production of such computers has reduced by the end of the previous year.

3. I can’t do the exercise. I had forgotten my text-book at home.

4. The article just translates by all the students.

5. By the time Kate returned from her studies, her brother goes to his friends.

6. His graduation paper will present by 3 o’clock tomorrow.

7. He is doing this work by tomorrow.

8. The solution for the problem is found by the end of the meeting yesterday.

9. The students already pass their credits.

10. She is written her course-paper by next month.

11. The advantages of this program already spoke of by the scientists at the conference.

12. The algorithm carefully hadn’t worked out at the recent seminar yet.

Ex.14. Ask special questions using question words given in parentheses.