Fill in the blanks:
(i) The curves which have different beginning and end points are called ...............
(ii) A curve which does not cross itself at any point is called a ...............
(iii) A simple closed curve made up entirely of line segments is called a ...............
(iv) A polygon in which each interior angle is less than 180° is called a ...............
(v) 10 sided polygon is called ...............
(vi) A polygon which has all its sides of equal length and all its angles of equal measure is called a ...............
(vii) Sum of all exterior angles of a polygon is ...............
(viii) Sum of all interior angles of a n-sided polygon is ...............
(ix) The adjacent angles of a parallelogram are ...............
(x) If an angle of a parallelogram is a right angle, then it is called a ...............
(xi) If two adjacent sides of a parallelogram are equal, then it is called a ...............
(xii) If two adjacent sides of a rectangle are equal, then it is called a ...............
(xiii) The diagonals of a rhombus bisect each other at ...............
(xiv) A quadrilateral in which one pair of opposite sides is parallel is called a ...............
(xv) A quadrilateral in which two pairs of adjacent sides are equal is called a ...............
(xvi) If two non-parallel sides of a trapezium are equal then it is called ...............
Answer
(i) The curves which have different beginning and end points are called open curves.
(ii) A curve which does not cross itself at any point is called a simple curve.
(iii) A simple closed curve made up entirely of line segments is called a polygon.
(iv) A polygon in which each interior angle is less than 180° is called a convex polygon.
(v) 10 sided polygon is called decagon.
(vi) A polygon which has all its sides of equal length and all its angles of equal measure is called a regular polygon.
(vii) Sum of all exterior angles of a polygon is 360°.
(viii) Sum of all interior angles of a n-sided polygon is (n - 2) × 180°.
(ix) The adjacent angles of a parallelogram are supplementary.
(x) If an angle of a parallelogram is a right angle, then it is called a rectangle.
(xi) If two adjacent sides of a parallelogram are equal, then it is called a rhombus.
(xii) If two adjacent sides of a rectangle are equal, then it is called a square.
(xiii) The diagonals of a rhombus bisect each other at right angles.
(xiv) A quadrilateral in which one pair of opposite sides is parallel is called a trapezium.
(xv) A quadrilateral in which two pairs of adjacent sides are equal is called a kite.
(xvi) If two non-parallel sides of a trapezium are equal then it is called an isosceles trapezium.
State whether the following statements are true (T) or false (F):
(i) The curves which have same beginning and end points are called open curves.
(ii) The region of the plane that lies inside the curve is called interior of curve.
(iii) A polygon in which atleast one interior angle is greater than 180° is called convex polygon.
(iv) 6 sided polygon is called hexagon.
(v) Sum of all interior angles of a quadrilateral is 180°
(vi) Each interior angle of a -sided regular polygon is
(vii) The diagonals of a parallelogram bisect each other at right angles.
(viii) The opposite angles of a parallelogram are equal.
(ix) The diagonals of a rhombus bisect the angles of rhombus.
(x) The diagonals of a square are not equal.
(xi) Co-interior angles of a parallelogram are supplementary.
(xii) The diagonals of a kite bisect at right angles.
(xiii) All rectangles are squares.
(xiv) All rhombuses are parallelograms.
(xv) All squares are rhombuses and also rectangles.
(xvi) All squares are not parallelograms.
(xvii) All kites are rhombuses.
(xviii) All rhombuses are kites.
(xix) All parallelograms are trapeziums.
(xx) All squares are trapeziums.
Answer
(i) The curves which have same beginning and end points are called open curves.
False
The curves which have the same beginning and end points are called closed curves.
(ii) The region of the plane that lies inside the curve is called interior of curve.
True
(iii) A polygon in which atleast one interior angle is greater than 180° is called convex polygon.
False
A polygon in which atleast one interior angle is greater than 180° is called a concave polygon.
(iv) 6 sided polygon is called hexagon.
True
(v) Sum of all interior angles of a quadrilateral is 180°
False
The sum of all interior angles of a quadrilateral is 360°.
(vi) Each interior angle of a -sided regular polygon is
True
(vii) The diagonals of a parallelogram bisect each other at right angles.
False
The diagonals of a parallelogram bisect each other, but not necessarily at right angles.
(viii) The opposite angles of a parallelogram are equal.
True
(ix) The diagonals of a rhombus bisect the angles of rhombus.
True
(x) The diagonals of a square are not equal.
False
The diagonals of a square are equal in length.
(xi) Co-interior angles of a parallelogram are supplementary.
True
(xii) The diagonals of a kite bisect at right angles.
False
The diagonals of a kite intersect at right angles, but only one diagonal bisects the other.
(xiii) All rectangles are squares.
False
All squares are rectangles, but all rectangles are not squares.
(xiv) All rhombuses are parallelograms.
True
(xv) All squares are rhombuses and also rectangles.
True
(xvi) All squares are not parallelograms.
False
All squares are parallelograms.
(xvii) All kites are rhombuses.
False
All rhombuses are kites, but all kites are not rhombuses.
(xviii) All rhombuses are kites.
True
(xix) All parallelograms are trapeziums.
True
(xx) All squares are trapeziums.
True