45-degree Kites are actually the same shape as 4 Point Stars, but these are measured by the short edge instead of the long one.
What difference does it make? If you want the short edge to match up with other shapes like octagons or 8-point diamonds, use these ones. The long edge will be an unusual length that won't match with anything but itself, making it perfect for these Wintergreen flowers pictured. If you want the long edge to match up, use the 4 Point Star. The short edge of a 4 Point Star can only match with itself.