What statement is not true

Question

Which statement is not true sin 20=cos70 or sin 45=cos45 or sin 35=cos55 or sin 260=cos100

Answer 1

1st three are true because sin(x) = cos(90-x)

For last one:

sin(260) = -sin(80)

cos(100) = -cos(80)

-sin(80) != -cos(80)