 Hello and welcome to the session. Let us understand the following question which says, fill in the blanks using the correct word given in brackets. First, all circles are dash, congruent or similar. Second, all squares are dash, similar or congruent. Third, all dash triangles are similar. Isosceles or equilateral. Fourth, two polygons of the same number of sides are similar. If A, their corresponding angles are dash and B, their corresponding sides are dash, equal or proportional. Now let's proceed on to the solution. Let us first understand the concept of congruent figures and similar figures. Two figures having same shape and the same size are called congruent figures. Now similar figures, two figures having same shape but not necessarily the same size are called similar figures. So now if we have circles of different radii's then they have same shape but different size so they are similar. So by property of similar figures, all circles are similar. Hence we can write here all circles are similar. Similarly for squares, two squares have same shape but not same size so again my property of similar figures, all squares are similar. In an isosceles triangle the sides of the triangle are different so they don't have the same shape. Hence the isosceles triangles are not similar and in an equilateral triangle all the sides are same so all equilateral triangles are similar. Therefore we can write all equilateral triangles are similar. Now let us understand the concept of similarity of two polygons. Two polygons of the same number of sides are similar, their corresponding angles are equal and second their corresponding sides are in the same ratio or proportion. So here we can say that two polygons of the same number of sides are similar if A their corresponding angles are equal and B their corresponding sides are proportional. Hence we have finally all circles are similar, all squares are similar, all equilateral triangles are similar. Two polygons of the same number of sides are similar if A their corresponding angles are equal and B their corresponding sides are proportional. I hope you understood this question that's all for the session. Bye and have a nice day.