sin²1°+sin²2°+sin²3°...+sin²45°+sin²46°...+sin²89°
＝sin^2(90-89)+sin^2(90-88)+...sin^2(90-46)+...+sin²45°+sin²46°...+sin²89°
=(cos89)^2+(cos88)^2+.+sin²45°+sin²46°...+sin²89°
=44+1/2
＝44.5