MATHS GK

Class-9

1. Who is widely considered to be the “Father of Mathmatics”?
Ans: Archimedes
2. “Number rules the universe” who said it?
Ans: Pythagoras
3. What number do you get when you multiply all of the numbers on a telephone number pad?
Ans: Zero
4. What are integers?
Ans: The group of whole numbers together with negative numbers are called intergers.(-3,-2,-1,0,1,2,3)
5. What is Polynomial?
Ans:Polynomial is such an expression which have one or more than one term.Ex-4x²-3x+7
6. What are Perfect Squares?
Ans: A natural number is called a perfect square, if it is the square of a number.
7. What is area of trapezium?
Ans: ½(Sum of parallel sides)x(Height)
8. What is area of triangle using Heron’s formula?
Ans: √s(s-a)(s-b)(s-c)
Where a,b,c are the sides of triangle. S is the semiperimeter=(a+b+c)/2
9. Write the formula to finding the area of four walls.
Ans: 2 x Height (Length + Breadth)
10. What is volume of Right Circular Cylinder?
Ans: (Area of base)xHeight                
( πr ²) x h = πr ²h
11. What is curved surface area of Right circular Cylinder?
Ans: (Circumference of the base) x (Height )
 (2πr) x h=2πrh
12. How many Faces in Rectangular Prism?
Ans: 8 faces
13. What is average speed?
Ans: Average speed=(Total distance travelled)/(Time Taken)
14. How we convert the speed of meter per second into kilometer per hour?
Ans: m/s=km/h [By multiplying 3600/1000]
20 m/s = 20 x (3600/1000)=72Km/h
15. How we convert the speed of kilometer per hour into meter per second?
Ans: Km/h=m/s [By multiplying 1000/3600]
16. Write two properties of parallelogram.
Ans: 1. Opposite sides are equal. 2. Opposite angles are equals.
17. Write two properties of square?
Ans: 1. All sides are equal. 2. All angles are measures 90°
18. 1 Hectare =10,000 square
19. Write the formula of Volume of cone.
Ans: 1/3πr ³h
20. Write the formula of Volume of Sphere.
Ans: 4/3πr ³

Class-8

1. Write two rational numbers which are their own reciprocals.
Ans: 1 and -1
2. Which rational number is the multiplicative identity for rational numbers?
Ans: 1
3. What is additive identity for rational numbers?.
Ans: 0
4. What is Reflex Angles?
Ans: Angles which lie between 180° to 360°.
5. What are Adjacent Angles?
Ans: Two angles are said to be adjacent if they have a common vertex and a common arm are called adjacent angles.
6. What are Linear Pair Angles?
Ans: A pair of adjacent angles is said to form a linear pair , if their non-common arms lie on one line.
7. What are Transversal Lines?
Ans: A line which cut two or more given lines at different points are called transversal lines.
8. What are Congruent Objects?
Ans: Two objects having the same shape and size are called congruent objects.
9. What is RHS Congruence Condition?
Ans: Two right triangles are congruent, if the hypotenuse and one side of one triangle are equal to side of other triangle.
10. Write the formula to find Area of Triangle.
Ans: 1/2*Base*Height 
11. Write the formula to find Area of Circle?
Ans:   πr²     [π=22/7,r=Radius]  
12. What is Proportion?
Ans: When two ratios are equal, then their terms are said to be in proportion. Ex- 2:3 and 8:12 are equals hence they are in proportion.
13. What are variables?
Ans: A symbol which can take various numerical values is called variable. For example – a,b,x,y.
14. What are Constants?
Ans: A symbol with fixed numerical value are called constants. For ex- 7,2,-1,2/3
15. Write the formula to find Arithmetic mean.
Ans: Arithmetic mean=(Sum of all observation)/(Number of observation)
16. Write the formula to find Area of Equilateral Triangle.
Ans: √3/4*(side)2
17. What is Speed?
Ans: Speed is the distance traveled by a moving body per unit time. [Speed=Distance/Time]
18. What is Principal (P)?
Ans: The amount of money borrowed is called the Principal.
19. What is Simple Interest?
Ans: The extra amount paid back for using the borrowed money is called the simple interest. It is denoted by (S.I).
20. What is Amount?
Ans: The total of the principal and the interest is called amount denoted by (A).

Amount(A)=Principal+Interest

Class-7

1. What is the name of longest side of a right triangle?
Ans: Hypotenuse
2. What are three positive numbers give the same result when multiplied and added together?
Ans: 1,2,3
Check-1x2x3=6, 1+2+3=6
3. The name of the polygon that has 15 Sides.
Ans: Pentadecagon
4. What is the other name of the perimeter of a circle?
Ans: Circumference
5. What is a solid shape that has four equal triangular faces?
Ans: Tetrahedron
6. What is acute Angles Triangle?
Ans: The Triangle in which all angles are less than 90° is called Acute Angled Triangle.
7. What is obtuse angles triangle?
Ans: The Triangle in which one angle is greater than 90° is called obtuse angled triangle.
8. What are Intersecting Lines?
Ans: Two lines cut each other called Intersecting Lines.
9. What is Perpendicular Lines?
Ans: Two Lines cuts each other at 90° called Perpendicular lines.
10. What is the right angle triangle?
Ans: 90° 
11. What is complement angles?
Ans: When sum of two angles is 90° called complement angles. For ex- (30°,60°), (40°,60°)
12. What is Supplement angle?
Ans: When sum of two angles is called 180° is called Supplement angle. For ex- (60°,120°), (130°,150°)
13. What is Pythagoras Theorem?
Ans: In a right triangle , the Square of the hypotenuse equals to sum of the squares of its remaining two sides.
(Hypotenus)²=(Base) ²+(Perpendicular) ²
14. Write the formula to find perimeter of circle.
Ans: 2πr    [π=22/7  r=radius]
15. Write the formula to find Area of Rhombus.
Ans: 1/2*(1st diagonal)*(2nd Diagonal)or 1/2*Base*Height
16. Write the formula to find Perimeter of Rhombus.
Ans: 4*Side
17. What are concentric circles?
Ans: Two or more circles having same centre are called concentric circles.
18. What is side-side-side congruence condition?
Ans: Two Triangles are congruent, if the three sides of one triangle are equal to three sides of other triangle.
19. What is side-angle-side congruence condition?
Ans: Two Triangles are congruent ,if the two sides and the included angle of one triangle are equal to two sides and the included angles of the other triangle.
20. Write Euler’s Formula.
Ans: V+F=E+2

Vertices+Faces=Edged+2

Class-6

1. What is the total number of dots on a dice?
Ans: 21
2. What is the only even prime number?
Ans: 2
3. How many seconds are there in one hour?
Ans: 3600 seconds
4. What are Prime Numbers?
Ans: The number which divide by only 1 and itself . for ex- 2,3,5,7,11
5. What are Composite Numbers?
Ans: Numbers having more than two distinct factors are known as composite numbers. For ex- 8,10,15,18
6. What are the Co-prime numbers?
Ans: Two numbers are said to be co-prime ,if their HCF is 1. For ex- (9,10)
Factor of 9=3*3x*1
Factor of 10=2*5*1
HCF of 9 and 10=1, so (9,10) are co-prime.
7. What are Perfect numbers?
Ans: A number which is equal to sum of its factors other than itself is called a perfect number. For ex- 6
Factor of 6=1,2,3,6 (1+2+3=6) ,So 6 is Perfect number.
8. What are Acute Angles?
Ans: These angles lies between 0° to 90°  is called acute angles. For ex- 20°,55°,70°
9. What are Obtuse Angle?
Ans: Those angles which lie between 90° to 180°  are called Obtuse Angle. For ex- 105°,150°,170°
10. What is the right angle?
Ans: 90° angle is right angle.
11. What is scalene Triangle?
Ans: A triangle having all sides different in length are called Scalene Triangle.
12. What is Isosceles Triangle?
Ans: If any two sides of a triangle are equal called Isosceles Triangle.
13. What is Equilateral Triangle?
Ans: If all the sides of a triangle are equal, is called Equilateral Triangle.
14. What is the sum of all angles of a triangle?
Ans: 180°
15. What is the formula to find the Perimeter?
Ans: Perimeter= Sum of all sides.
16. Write the formula to find the Perimeter of Square.
Ans: 4*Side
17. Write the formula to find the Perimeter of Rectangle.
Ans: 2*(Length+Breadth)
18. Write the formula to find the Perimeter of Equilateral Triangle.
Ans: 3*Side
19. Write the formula to find the Area of Rectangle.
Ans: Length * Breadth
20. Write the formula to find the Area of Square.

Ans: Side*Side