75
edits
Changes
Jump to navigation
Jump to search
Line 248:
Line 248: − + + + + + + + + + + + + + + + + + + + + + + + +
→Hints for difficult problems
*Question Corner
*Question Corner
= Hints for difficult problems =
[[:File:polygon problem.odt]]= Hints for difficult problems =
CLASS IX TOPIC POLYGONS
ADDITIONAL PROBLEMS (problem no 3 )
A polygon has 'n' sides .Two of it's angles are right angles and each of remaining angle isFind the value of 'n'.
Step 1;(Students must understand the problem)
In a polygon of side 'n' two angles are and other angles are each.We must find out value of 'n'.
Step 2(Students know the formula for sum of angles of polygon of side 'n')
(2n-4)right angles.
Step 3(Sum of the angles is equal to what?)
There are 'n' angles in a polygon of side 'n'.Out of 'n' angles 2 angles are right anles and other (n-2) angles are each.
(2n-4) <math>90^0</math> = (n-2)<math>\144^0+{2}{90}^0</math>Students know how to open the bracket and substitute the values)
2n x - 4 x =
= (Brings similar terms at one side of the equation)
= (Add and substract and simplify)
=
n = (Devide and simplify)
n = 7
= Project Ideas =
= Project Ideas =