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<!DOCTYPE html>
<title>CSS Shapes: polygon() rounding clamping reference</title>
<style>
.test {
display: inline-block;
width: 200px;
height: 200px;
background: green;
margin: 10px;
}
/* Rectangle: exact clamped radius = tan(45deg) * 200/2 = 100px. */
.t1 {
clip-path: polygon(round 100px, 0 0, 100% 0, 100% 100%, 0 100%);
}
/* Pentagon and isosceles triangle: vertices have non-uniform angles, so
use round 9999px which must clamp to the same max as the test file. */
.t2 {
clip-path: polygon(round 9999px, 50% 0%, 100% 38%, 82% 100%, 18% 100%, 0% 38%);
}
.t3 {
clip-path: polygon(round 9999px, 50% 0%, 0% 100%, 100% 100%);
}
/* Equilateral triangle: exact clamped radius = tan(30deg) * 200/2. */
.t4 {
height: auto;
aspect-ratio: 1 / sin(60deg);
clip-path: polygon(round calc(tan(30deg) * 100px), 50% 0%, 0% 100%, 100% 100%);
}
/* Diamond: exact clamped radius = tan(45deg) * 100*sqrt(2)/2 = 50*sqrt(2). */
.t5 {
clip-path: polygon(round calc(50px * sqrt(2)), 50% 0%, 100% 50%, 50% 100%, 0% 50%);
}
</style>
<p>The test passes if all five shapes match their references.</p>
<div class="test t1"></div>
<div class="test t2"></div>
<div class="test t3"></div>
<div class="test t4"></div>
<div class="test t5"></div>