# What is a 45-45-90 triangle? Please give an example.

Nov 14, 2015

it's any isoceles right triangle.

#### Explanation:

Example: Cartesian plane points

$A = \left(0 , 0\right)$

$B = \left(t , 0\right)$

$C = \left(0 , t\right)$

$t > 0$

$A B = t$

$A C = t$

$B {C}^{2} = {t}^{2} + {t}^{2} R i g h t a r r o w B C = t \sqrt{2}$

angle BAC = 90º

A + B + C = 180º

AB = AC Rightarrow angle B = angle C = (180º - 90º)/2

For two values ${t}_{1} , {t}_{2}$, we have two similar triangles ${B}_{1} A {C}_{1} \cong {B}_{2} A {C}_{2}$