# Which 2 digit number is a square number as well as triangular number?

## Which 2 digit number is a square number as well as triangular number?

25,36,4964 Ans. (4) Write the greatest two digit square numbers as well as triangular numbers. Ans. Q.

What is the triangle number?

A triangular number is a number that can be represented by a pattern of dots arranged in an equilateral triangle with the same number of dots on each side. The first triangular number is 1, the second is 3, the third is 6, the fourth 10, the fifth 15, and so on.

### Is both a square and a triangular number?

In mathematics, a square triangular number (or triangular square number) is a number which is both a triangular number and a perfect square.

Which of the following is both a square and a triangular number?

Answer: 36 is the number which represents both triangular number and square number. Step-by-step explanation: as you can see in the below picture.

#### Is 18 a triangular number?

List Of Triangular Numbers. 0, 1, 3, 6, 10, 15, 21, 28, 36, 45, 55, 66, 78, 91, 105, 120,136, 153, 171, 190, 210, 231, 253, 276, 300, 325, 351, 378, 406, 435, 465, 496, 528, 561, 595, 630, 666, 703, 741, 780, 820, 861, 903, 946, 990, 1035, 1081, 1128, 1176, 1225, 1275, 1326, 1378, 1431, and so on.

How do you work out a triangular number?

1. Triangular numbers are a pattern of numbers that form equilateral triangles.
2. The formula for calculating the nth triangular number is: T = (n)(n + 1) / 2.

## What are the first 3 square numbers?

Square Numbers It is called a square number because it gives the area of a square whose side length is an integer. The first square number is 1 because. The first fifteen square numbers are: 1, 4, 9, 16, 25, 36, 49, 64, 81, 100, 121, 144, 169, 196 and 225.

Is 20 a triangular number?

0, 1, 3, 6, 10, 15, 21, 28, 36, 45, 55, 66, 78, 91, 105, 120, 136, 153, 171, 190, 210, 231, 253, 276, 300, 325, 351, 378, 406, 435, 465, 496, 528, 561, 595, 630, 666… (This sequence is included in the On-Line Encyclopedia of Integer Sequences (sequence A000217 in the OEIS)).

### What is the formula for finding triangular numbers?

Triangular numbers are a pattern of numbers that form equilateral triangles. The formula for calculating the nth triangular number is: T = (n)(n + 1) / 2.

How do you know if a number is a triangular number?

A number is termed as triangular number if we can represent it in the form of triangular grid of points such that the points form an equilateral triangle and each row contains as many points as the row number, i.e., the first row has one point, second row has two points, third row has three points and so on.

#### Why is 28 the perfect number?

A number is perfect if all of its factors, including 1 but excluding itself, perfectly add up to the number you began with. 6, for example, is perfect, because its factors — 3, 2, and 1 — all sum up to 6. 28 is perfect too: 14, 7, 4, 2, and 1 add up to 28.

Is 3 a square number?

Thus, 3 is the only prime number one less than a square. A square number is also the sum of two consecutive triangular numbers.