A straight eight engine has eight cylinders all in a stright line. In contrast a V8 engine has 8 cylinders with 4 cylinders on each side of the V formation. This produces a shorter block.
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It's kind of obvious seeing as 'oct' means eight... Anyway, there are eight straight lines in an octagon.
Octogon
Straight.
octagon !
Eight straight lines, meeting in pairs at eight vertices.
You can cut a round cake into eight parts with three cuts, but you can't cut a circle into eight parts with three straight lines.
Octogon. Eight sides, think of OCTOpus which has eight legs.
Eight Straight.
next to the oil pan facing straight down towards the ground
1949 Buick Eight Road Master Convertable
There is no specific name for such a shape.