# Supplementary Angles

Posted in Terms Defined

When the sum of the measures of two angles is 180°, the angles are called supplementary angles.

For examples the following pairs are complementary:

(a) 30° and 150°

(b) 145° and 35°

(c) 100° and 80°

When two angles are complementary, each angle is said to be the supplement of the other angle. The '100° angle' is supplement of the '80° angle'.

# Complementary Angles

Posted in Terms Defined

When the sum of the measures of two angles is 90°, the angles are called complementary angles.

For examples the following pairs are complementary:

(a) 30° and 60°

(b) 45° and 45°

(c) 10° and 80°

When two angles are complementary, each angle is said to be the complement of the other angle. The '10° angle' is complement of the '80° angle'.

# Range of Observations

Posted in Terms Defined

The difference between the highest and lowest observation is called the range of the observations.

For example, consider the following observations:

2, 10, 5, 34, 98, 54

The highest observation is 98 and the lowest observation is 2.

So, the range of the observation is

= 98 - 2

= 96

# Important Statements

Posted in Terms Defined

• A factor of a number is an exact divisor of that number.
• A number for which sum of all its factors is equal to twice the number is called a perfect number.
• The numbers other than 1 whose only factors are 1 and the number itself are called Prime numbers.
• Numbers having more than two factors are called Composite numbers.

# Fraction

Posted in Terms Defined

A fraction means a part of a group or of a region.

for example $$\frac{2}{3}$$ is a fraction

where 2 is numerator and 3 is denominator.

Proper Fraction - In a proper fraction the numerator is always less than the denominator. For example $$\frac{4}{7}$$, $$\frac{21}{43}$$

Improper Fraction - In a improper fraction the denominator is always less than the numerator. For example $$\frac{7}{4}$$, $$\frac{43}{21}$$

Mixed Fractions - A mixed fraction has a combination of a whole and a part. For example $$3 \frac{1}{2}$$, $$7 \frac{4}{7}$$