# Thread: how to factorise when given 2 squares

1. ## how to factorise when given 2 squares

How could I factorise this?

a^2+100a-100b+40ab+b^2

I know it's a square number so I must be able to factorise it into something along the lines of (...)^2

2. suppose its a trionym with unknown letter a and b known.
$${a^2} + \left( {100 + 40b} \right)a + {b^2} - 100b$$

3. I don't think it's a trinomial... I've researched those types of equations and I don't think it's possible to factorise... my mistake, sorry.