Question

is both a triangular number and a squqre numbers a,10 ,b)25 c)36 d)15​

Answer 1

Answer:

Step-by-step explanation:

WHAT IS A TRIANGULAR NUMBER.

IT IS A NUMBER THAT FORMS AN EQUILATERAL TRIANGLE

IT CAN BE DEFINED AS 1+2+3+4+5+...+n=n(n+1)/2

25and36 are squares.

now let n=8

8(8+1)/2=4 x 9=36 so 36 is a square and a triangular number.

for triangular number representation look at the attachment below

pls mark my answer brainliest.

note that is got as 8 by pure trial and error method

and this formula above n(n+1)/2 is very helpful in examinations

for eg if the ask  you till 5 you can add it manually

but if asked till 1-100 or 1-200  then you cant sit and at each number.

1+2+3+4+5+6+7+........+n=n(n+1)/2