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The longest chord passes through the centre of the circle (view source)
Revision as of 17:52, 4 December 2013
, 17:52, 4 December 2013→Concept # Cyclic quadrilateral
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+ + + + + + Developmental Questions+
# The teacher can recall the concept of a circle, quadrilateral, circumcircle.
# The teacher can recall the concept of a circle, quadrilateral, circumcircle.
# Can explain a cyclic quadrilateral and show the geogebra applet.
# Can explain a cyclic quadrilateral and show the geogebra applet.
−# Move points, the vertices of the quadrilateral and let the students observe the opposite interior angles.
+# Move points, the vertices of the quadrilateral and let the students observe the sum of opposite interior angles.
Developmental Questions:
Developmental Questions:
# What two figures do you see in the figure ?
# What two figures do you see in the figure ?
−# Name the vertices of the triangle.
+# Name the vertices of the quadrilateral.
# Where are all the 4 vertices situated ?
# Where are all the 4 vertices situated ?
# Name the opposite interior angles of the quadrilateral.
# Name the opposite interior angles of the quadrilateral.
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*Prerequisites/Instructions, if any
*Prerequisites/Instructions, if any
# The students should know a circle and a quadrilateral.
# The students should know a circle and a quadrilateral.
−# They should follow the instructions carefully.
+# They should know that in a cyclic quadrilateral the sum of opposite interior angles is 180 degrees.
+# In a cyclic quadrilateral the exterior angle is equal to interior opposite angle
*Multimedia resources
*Multimedia resources
*Website interactives/ links/ / Geogebra Applets
*Website interactives/ links/ / Geogebra Applets
+This activity has been taken from the website http://mykhmsmathclass.blogspot.in/2007/11/class-ix-activity-16.html
*Process:
*Process:
# Draw a circle of any radius on a coloured paper and cut it.
# Draw a circle of any radius on a coloured paper and cut it.
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# Produce AB to form a ray AE such that exterior angle CBE is formed.
# Produce AB to form a ray AE such that exterior angle CBE is formed.
# Make a replica of angle ADC and place it on angle CBE . Write the observation.
# Make a replica of angle ADC and place it on angle CBE . Write the observation.
− Developmental Questions:
−# How do you take radius ?
−# What is the circumference ?
−# What is a chord ?
−# What is a quadrilateral ?
−# Where are all four vertices of a quadrilateral located ?
−# What part are we trying to cut and compare ?
−*Evaluation
+# What can you infer ?
−*Question Corner
+*Evaluation:
+# Angle BAD and angle BCD, when placed adjacent to each other on a straight line, completely cover the straight angle.What does this mean ?
+# Angle ABC and angle ADC, when placed adjacent to each other on a straight line, completely cover the straight angle.What can you conclude ?
+# Compare angle ADC with angle CBE.
+*Question Corner:
+Name the two properties of cyclic quarilaterals.
= Hints for difficult problems =
= Hints for difficult problems =