sin=opposite / hypotenuse
cos=adjacent / hypotenuse
tan=opposite / adjacent
Sin of A= opposite / hypotenuse
= 4 (sides of the right triangle are congruent, it's an isoscles) /

= 1/

=
Cos of A= adjacent / hypotenuse
= 4 /

= 1/ square root of 2
=

Tan of A=opposite / adjacent
= 4/4
= 1
Hope this helps :)