Fill in the blanks using the correct word given in brackets: (i) All circles are _____. (congruent, similar) (ii) All squares are _____. (similar, congruent) (iii) All _____ triangles are similar. (isosceles, equilateral) (iv) Two polygons of the same number of sides are similar, if (a) their corresponding angles are _____ and (b) their corresponding sides are _____. (equal, proportional)
similar
similar
equilateral
equal, proportional
Explanation
The answers are derived directly from the properties of similar figures as presented in the textbook context. The text explicitly states that all circles are similar and all squares are similar because they share the same shape regardless of size. It also specifies that all equilateral triangles are similar. For polygons, the text outlines the two necessary conditions for similarity: corresponding angles must be equal, and corresponding sides must be in the same ratio (proportional).