Three molecules with wedge and dash bonds
For each one we wrote out which way the bonds point, and added a SMILES string for anyone who wants to paste it into chemistry software.
The drawing
What we made
1. (R)-3-fluoro-2,3-dimethylpentane
A five carbon chain. Carbon 2 has a methyl group. Carbon 3 has a fluorine and a methyl group, and that methyl is drawn on a hashed bond, so it points away from you. Carbon 3 is a stereocenter, R configuration.
SMILES: CC[C@@](C)(F)C(C)C
2. meso-butane-2,3-diol, (2R,3S)
A four carbon chain with an OH on carbons 2 and 3. The methyl on carbon 2 is on a wedge (toward you) and the methyl on carbon 3 is on a hashed bond (away from you). Two stereocenters, one R and one S. It has an internal mirror plane, so it is achiral (meso).
SMILES: C[C@H](O)[C@@H](C)O
3. (S)-ibuprofen
A benzene ring with two groups on opposite sides. On one side is a 2-methylpropyl group. On the other is a carbon with a methyl on a wedge (toward you) and a carboxylic acid group. That carbon is a stereocenter, S configuration.
SMILES: CC(C)Cc1ccc(cc1)[C@H](C)C(=O)O
We checked all 4 stereocenters by rebuilding each molecule from the drawing in chemistry software and comparing.