Circles Class 9th Formulas -Maths 9th

Circles Class 9th Formulas -Maths 9th
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• Two geometric figures are congruent if they have the same shape and the same size. Corresponding parts of congruent triangles are congruent (equal) (c.p.c.t.c)  i.e.,if ΔABC ≅ ΔPQR  then ∠A = ∠P,  ∠B = ∠Q, ∠C = ∠ R, AB = PQ, BC = QR and AC = PR. There are five congruence criterion: 1.  SAS 2.  ASA 3. AAS 4.  SSS  5.  RHS 1.By SAS rule, if two sides and the included angle of one triangle are equal to two sides and the included angle of the other triangle, then the two triangles are congruent. 2.By ASA rule, if two angles and the included side of one triangle are equal to two angles and the included side of the other triangle, then the two triangles are congruent. 3. By AAS rule, if two angles and any one side of one triangle are equal to two angles and corresponding side of the other triangle, then the two triangles are congruent. 4. By SSS rule, if three sides of one triangle are equal to three sides of the other triangle then the two triangles are congruent. 5. By RHS rule, if in two right angled triangle, one side and the hypotenuse of a triangle are equal to one side and the hypotenuse  of the other triangle then the two triangles are congruent. • In a triangle Angles opposite to equal sides are equal. Sides opposite to equal angles are equal. Angles opposite to the longer side is greater. Side opposite to the greater angle is longer. Sum of any two sides is greater than the third side. Difference of any two sides is always less than the third side.
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Description : The class marks of a frequency distribution are 104, 114, 124, 134, 144, 154, 164. -Maths 9th

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Description : Following is the frequency distribution of total marks obtained by the students of different section of class-IX. -Maths 9th

Last Answer : Since class intervals of the given frequency distribution are not of equal width. We would make modifications in the lengths of the rectangles in the histogram, so that the areas of rectangles are proportional ... lengths as given in the last column .The histogram of the data is given below.

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Description : Following table gives the distribution of students of sections A and B of a class according to the marks obtained by them. -Maths 9th

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Description : In a class, there are x girls and y boys, a student is selected at random, then find the probability of selecting a boy. -Maths 9th

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Last Answer : You should study them thoroughly so that you won't find them difficult when you are preparing for competitive exams like Olympiad s,etc. Study other reference books along with ncert textbook. Hope my and will help you.

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Description : The class marks of a frequency distribution are 104, 114, 124, 134, 144, 154, 164. -Maths 9th

Last Answer : Since the class marks are equally spaced. ∴ Class size = 114 - 104 = 10 If a is a class mark and h is size of class interval, then lower limit and upper limit of the class interval area a - h / 2 and a + h / ... are 99 - 109, 109 - 119, 119 - 129, 129 - 139, 139 - 149, 149 - 159, 159 - 169.

Following is the frequency distribution of total marks obtained by the students of different section of class-IX. -Maths 9th

Description : Following is the frequency distribution of total marks obtained by the students of different section of class-IX. -Maths 9th

Last Answer : Since class intervals of the given frequency distribution are not of equal width. We would make modifications in the lengths of the rectangles in the histogram, so that the areas of rectangles are proportional ... lengths as given in the last column .The histogram of the data is given below.

Following table gives the distribution of students of sections A and B of a class according to the marks obtained by them. -Maths 9th

Description : Following table gives the distribution of students of sections A and B of a class according to the marks obtained by them. -Maths 9th

Last Answer : Clearly, the mean score of two sections A and B is same

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Last Answer : Total number of students = 10 + 13 + 12 + 5 = 40 Number of students having blood group ‘B’ = 12 Required probability =12 / 40 = 3 / 10

In a class, there are x girls and y boys, a student is selected at random, then find the probability of selecting a boy. -Maths 9th

Description : In a class, there are x girls and y boys, a student is selected at random, then find the probability of selecting a boy. -Maths 9th

Last Answer : Number of boys = y Total students = (x + y) Thus,P(a boy)= y/(x+y)

The given table shows the month of birth of 40 students of class IX of a particular section in a school. -Maths 9th

Description : The given table shows the month of birth of 40 students of class IX of a particular section in a school. -Maths 9th

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Last Answer : NEED ANSWER

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Last Answer : NEED ANSWER

The width of each of five continuous classes in a frequency distribution is 5 and the lower class limit of the lowest class is 10. -Maths 9th

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Last Answer : NEED ANSWER

If m is the mid-point and l is the upper class limit of a class in a continuous frequency distribution, then lower class limit of the class is -Maths 9th

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Last Answer : NEED ANSWER

The class marks of a frequency distribution are given as follows 15, 20, 25, …. The class corresponding to the class mark 20 is -Maths 9th

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