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Question 2:
How many diagonals does each of the following have?
(a) A convex quadrilateral
(b) A regular hexagon
(c) A triangle
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Question 3:
What is the sum of the measures of the angels of a convex quadrilateral? Will this property hold if the quadrilateral is not convex? (Make a non-convex quadrilateral and try!)
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Question 4:
Examine the table. (Each figure is divided into triangles and the sum of the angles deduced from that.)
Figure | ||||
Side | 3 | 4 | 5 | 6 |
Angle sum | 180° | 2 × 180° = (4 − 2) × 180° | 3 × 180° = (5 − 2) × 180° | 4 × 180° = (6 − 2) × 180° |
What can you say about the angle sum of a convex polygon with number of sides?
(a) 7
(b) 8
(c) 10
(d) n
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Question 5:
What is a regular polygon?
State the name of a regular polygon of
(i) 3 sides
(ii) 4 sides
(iii) 6 sides
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Question 2:
Find the measure of each exterior angle of a regular polygon of
(i) 9 sides
(ii) 15 sides
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Question 3:
How many sides does a regular polygon have if the measure of an exterior angle is 24°?
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Question 4:
How many sides does a regular polygon have if each of its interior angles is 165°?
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Question 5:
(a) Is it possible to have a regular polygon with measure of each exterior angle as 22°?
(b) Can it be an interior angle of a regular polygon? Why?
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Question 6:
(a) What is the minimum interior angle possible for a regular polygon?
(b) What is the maximum exterior angle possible for a regular polygon?
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Question 3:
Can a quadrilateral ABCD be a parallelogram if
(i) ∠D + ∠B = 180°?
(ii) AB = DC = 8 cm, AD = 4 cm and BC = 4.4 cm?
(iii) ∠A = 70° and ∠C = 65°?
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Question 5:
The measures of two adjacent angles of a parallelogram are in the ratio 3:2. Find the measure of each of the angles of the parallelogram.
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Question 10:
Explain how this figure is a trapezium. Which of its two sides are parallel?
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Question 10:
Explain how this figure is a trapezium. Which of its two sides are parallel?
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Question 12:
Find the measure of ∠P and ∠S, if in the following figure. (If you find m∠R, is there more than one method to find m∠P?)
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Question 2:
Identify all the quadrilaterals that have
(a) four sides of equal length
(b) four right angles
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Question 3:
Explain how a square is.
(i) a quadrilateral
(ii) a parallelogram
(iii) a rhombus
(iv) a rectangle