Things You'll Need
A semicircle is the foundation for many crocheted projects, such a shawls and sofa tablecloths. The semicircle pattern is also used to make rainbow motifs and clutch purses. Unlike a crocheted circle, which is worked in rounds, the semicircle is worked in rows. The semicircle begins in the center of the straight edge. Concentric rows are added to enlarge the semicircle. Stitch increases prevent the semicircle from curling. This pattern is well suited to the advanced novice crocheter; however, rows of intermediate-level crochet stitches may be substituted to create visual interest.
Make a sliding-loop slipknot. Chain one, then crochet four single-crochet stitches in the slipknot. This pattern is worked with only single-crochet and chain stitches. Chain one, then turn to begin the second and each consecutive row. Do two single-crochet stitches in each of the four single-crochet stitches from the previous row. Chain one, then turn.
Crochet the third row with one single-crochet stitch in the first stitch, then two in the second stitch. Two stitches in the same stitch are called a stitch increase. Continue alternating one stitch, then two, as you work across the third row. Continue until you reach the end. Chain one, then turn. Pull the loose thread in the sliding slipknot to tighten the loop.
Crochet one stitch in each of the first two stitches, then do a stitch increase in the third stitch. Continue with this alternating pattern, across the fourth row. As you crochet each consecutive row, increase the number of stitches by one, between each stitch increase. The fifth row will have one stitch in each of three stitches from the previous row, then a stitch increase. The sixth row will have one stitch in each of four stitches from the previous row, then a stitch increase, and so on.
Continue adding rows until the semicircle reaches the desired size. After the final stitch, tie off the yarn and weave in loose ends.