Page 59 - Mathematics Class - X

Viva-Voce

1. What is the relation between the triangles if the areas of two similar triangles are equal?
Ans. These triangles will be congruent to each other.

2. What is the area of an equilateral triangle, having its side as x unit?
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Ans. Area of equilateral triangle = x sq unit, where x is the side of equilateral triangle.
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3. What are the criteria used for similarity of two triangles?
Ans. (i) AAA similarity criterion (ii) AA similarity criterion

(iii) SSS similarity criterion (iv) SAS similarity criterion
4. If two isosceles triangles have equal angles and their areas are in the ratio 16 : 49, then find the ratio between
their corresponding heights?
Ans. The ratio of their corresponding heights = 4 : 7.

MCQs

1. In triangles ABC and DEF, ∠B = ∠E, ∠F = ∠C and AB = DE. Then, the two triangles are

a) congruent but not similar b) similar but not congruent
c) neither congruent nor similar d) congruent as well as similar

2. The criterion for similarity of two triangles is
a) AAA similarity criterion b) SSS similarity criterion
c) SAS similarity criterion d) All of these

3. Any two rectangles may be
a) Similar b) Congruent c) both (a) and (b) d) None of these

4. Are rectangle and square similar?
a) Yes b) No c) In some cases d) None of these
5. Which type of figures have the same shape but not necessarily the same size?

a) Similar figures b) Congruent figures c) Both (a) and (b) d) None of these

Answers: 1. d) congruent as well as similar 2. d) All of these 3. c) Both (a) and (b)
4. b) No 5. a) Similar figures

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