Math Terms StartingWith A

In this page math terms startingwith a we are going to see definitions of mathematical terms starting with the letter "A". We have listed out almost terms in math starting with A.In math also it is very important to know the meaning of many important words which are being used in the subject math.Each term is defined and examples are provided where ever it is necessary. Links are given for every words, by using this students can learn the meaning and its application more clearly.



AAA Similarity test

This is one of the three ways to test that two triangles are similar.Two triangles are said to be similar if the measure of three interior angles in one triangle are the same as the corresponding angles in another. Here ∠A and ∠R,∠B and ∠Q,∠C and ∠R are equal.

AAS congruence

This is one of the way to test the congruency of the triangles. It states that, Two triangles are said to be congruent, if two adjacent angles, and a side of one triangle are congruent with the corresponding angles and side of the other triangle.


Abacus is a counting tool used for early learners of math. It is also called as adding machine. It is a belief that this adding machine was used by early Aztecs in 300 BC. It is helping us in acquiring the ability to calculate accurately as well as rapidly. It is helping us to improve our ability to calculate mentally in more efficient manner. It helps provides concrete understanding of counting such as addition, subtraction, multiplication and division.

Absolute value

The absolute value of a number is its distance from 0 on a number line. For example, the number "5" and "-5" is 5 units away from zero. So its absolute value is 5 and -5 is 5. |5| = 5  |-5| = -5


An angle is nothing but the figure which is formed by the two rays, which are called as the two sides of that particular angle. Those two rays would have a common end endpoint which is known as vertex of that particular angle.

math terms startingwith a.

Acute angle

The angle which is less than 90 degree is called Acute angle.30 degree, 45 degree and 75 degree are some examples of acute angle. Because 30 degree, 45 degree and 75 degree, all these angles are less than 90 degree. So we call these angles as acute angle.

Alternate interior angles

In the following diagram the exterior angles 1 and 3 and 2 and 4 represents alternate exterior angles.

Alternate exterior angles

In the following figure the angles 1 and 3 and 2 and 4 are called as alternate exterior angles.

Adjacent angles

Refers to a pair of angles, that share a common vertex and side did not overlap. When referring to polygons, two interior angles that share a common side are also called as adjacent angles. It can also be called as adjacent interior angles of the polygon.


Height of an object above sea level.


In matrix adjoint refers to the transpose of co factor of the given matrix. It is denoted as adjA for a matrix A.


Algebra is a branch of math in which we use letters in the place of unknown values.


Explains how to solve a problem step by step instructions. You can understand how to take square root for any number you can refer the page square root algorithm.


The first alphabet of ancient Greece which is used in math and science.


Area is nothing but the quantity which exposes the extension of two dimensional surfaces.This is one of the most important sub topics.

Area of square

Area enclosed by the 4 equal sides is called the area of square. Area of the square = a²

Area of rectangle

Area enclosed by the pair of equal sides is called the area of rectangle. Area of rectangle = l x b

Area of quadrilateral

A shape which is having four sides is generally called quadrilateral. Area of quadrilateral = (1/2) x d x (h₁ + h₂).math terms startingwith a.

Area of triangle

Area covered by three sides is called area of triangle.

Area of triangle= (1/2) x Base x Height

Area of Sector

A part of the interior of a circle enclosed by an arc and two radii is called a sector of a given circle. Area of the sector = (θ/360) x Π r ² square units (or)  Area of the sector = (1/2) x l r square units  

Area of a parallelogram

A parallelogram is a quadrilateral in which opposite sides are parallel and equal in length. In other words opposite sides of a quadrilateral are equal in length then the quadrilateral is called a parallelogram. Area of parallelogram = b x h

Area of scalene triangle

Area covered by three unequal sides is called area of scalene triangle.

Area of scalene triangle = √s(s-a)(s-b)(s-c)

Area of trapezium

In US a quadrilateral which is having no parallel sides is called trapezium.Area = (1/2) (a + b) x h

Area of Rhombus

A quadrilateral which is having four equal sides is called rhombus. In other words a parallelogram will become rhombus if the diagonals are perpendicular.

Area of rhombus = (1/2) x (d₁ x d₂)

Area of  equilateral  triangle

Area covered by three equal sides of a triangle is called area of equilateral triangle.Area of Equilateral-triangle = (√3/4) a²

Area of circle

Area of circle means surface occupied by the figure. Here the shades portion is known as area of circle. Area = Π r ²

Area around circle

Area covered between two circle is called area around circle.

Area around circle = Area of big circle - area of small circle.math terms startingwith a.

Associative property

Associative property deals with grouping of elements under any operation.In other words, if a, b and c are elements of set A, and * is the operation, then a*(b*c) = (a*b)*c

Arithmetic series

Arithmetic series is nothing but sum of arithmetic terms.

sn = n2 [2a + (n-1)d]

sn = n2 [a + l]

Arithmetic sequence

A sequence is said to be an arithmetic sequence if the difference of each term,except the first one,from its preceding is always same.

Arithmetic Mean

Arithmetic mean means the sum of the given data, divided by the total values of the set.

Angle between two lines

Angle lies between two lines is called angle between two lines.

θ = tan-¹ |(m₁ - m₂)/(1 + m₁ m₂)|

Addition Table

Using addition table we can easily do addition.

Addition formula

Using addition formula we can easily add two fraction with out taking L.C.M

ab + cd = (ac + bd) bd


Addition is bringing two or more numbers (or things of same type) together.It is nothing but one of the binary operations along with subtraction, multiplication and division. By using this binary operation, we can combine two numerical values in to single numerical value. math terms startingwith a.


An asymptote to a curve is the tangent to the curve such that the point of contact is at infinity.

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