why duplicate mesh turns out different?

Support Modeling
1

hi, I was created a dining table. I duplicate mesh from top panel of table and attach it with original mesh. The duplicate mesh turns out half shadow of panel. I wonder why is it? I figure if something block from light direct to table but no other objects in way…The lamp direct spread around the kitchen includes table…

why is that.jpg1920×1080 774 KB

Help me to resolve by get rid of shadow half on duplicated mesh. it supposed to be like as oringal mesh…

2

select face, flip normals

3

I took your adivce and flipped it, shadow still there but less… shadow needs go away…

Attachments

flip normal is nto working.jpg1920×1080 592 KB

4

check if it is shade flat or smooth and remove doubles

5

yaya! i checked shade to flat and it works! Weird! Why smooth shade was clicked in the first place… obviously, I accidently click it. lol. Thank @doublebishop…