Geometric Shapes Complete Guide

Unicode dedicates an entire block to geometric shapes -- circles, squares, triangles, diamonds, and other polygons in filled, outlined, and variously styled forms. The Geometric Shapes block (U+25A0--U+25FF) contains 96 characters, supplemented by hundreds more in the Geometric Shapes Extended block, Block Elements, and Miscellaneous Symbols. This guide catalogs the major geometric characters, explains their organization, and demonstrates practical uses in interfaces, data visualization, and text design.

The Geometric Shapes Block (U+25A0--U+25FF)

This primary block contains 96 characters covering the fundamental geometric forms:

Squares and Rectangles

Unicode provides squares in multiple sizes -- large (■ □), medium (◻ ◼), medium-small (◽ ◾), and small (▪ ▫). The "black" variants are filled, "white" are outlined. This size progression enables multi-level bullet lists and visual hierarchies in plain text.

Circles

The half-filled and quarter-filled circles (◐ ◑ ◒ ◓ ◔ ◕) are particularly useful for representing partial progress, ratings, or pie-chart approximations in text-only contexts.

Triangles

Triangles come in all four directions and two sizes. The right-pointing triangle ▶ is commonly used as a play button, while ▲ and ▼ serve as sort indicators in table headers.

Diamonds

The lozenge ◊ is technically a different shape (taller and narrower than a diamond) and is used in pharmaceutical notation and mathematical typesetting.

Stars and Pentagons

Note that ★ and ☆ are in the Miscellaneous Symbols block, not Geometric Shapes. They are included here because they are used alongside geometric shapes in practice.

Block Elements (U+2580--U+259F)

The Block Elements block provides 32 characters for building box-drawing graphics and terminal-based visualizations:

Horizontal Blocks (Fractional Heights)

These characters progress from one-eighth height (▁) to full height (█), creating an eight-step vertical bar chart in a single character column.

Shade Characters

The shade characters are iconic in computing history -- they were essential in DOS-era text-mode user interfaces for creating shadows, gradients, and visual depth effects.

Vertical and Quadrant Blocks

The quadrant characters divide a cell into four quarters, enabling 2x2 pixel resolution per character -- useful for low-resolution graphics in terminals.

Practical Applications

Progress Bars

Block elements create compact text-based progress bars:

def progress_bar(percent, width=20):
    filled = int(width * percent / 100)
    bar = "\u2588" * filled + "\u2591" * (width - filled)
    return f"|{bar}| {percent}%"

print(progress_bar(75))
# |████████████████░░░░| 75%

Sparkline Charts

Block elements can approximate sparkline charts:

def sparkline(values):
    blocks = " \u2581\u2582\u2583\u2584\u2585\u2586\u2587\u2588"
    lo, hi = min(values), max(values)
    if lo == hi:
        return "\u2584" * len(values)
    return "".join(
        blocks[int((v - lo) / (hi - lo) * 7) + 1]
        for v in values
    )

data = [4, 8, 15, 16, 23, 42, 30, 12, 5, 1]
print(sparkline(data))
# ▁▂▃▃▄█▅▂▁▁

Rating Stars

def star_rating(score, max_score=5):
    full = int(score)
    half = 1 if score - full >= 0.5 else 0
    empty = max_score - full - half
    return "\u2605" * full + ("\u00BD" if half else "") + "\u2606" * empty

print(star_rating(3.5))
# ★★★½☆

CSS: Geometric Bullets

ul.diamond-list {
    list-style: none;
}
ul.diamond-list li::before {
    content: "\25C6 ";
    color: #2563eb;
}

ul.circle-list li::before {
    content: "\25CF ";
    color: #059669;
}

JavaScript: Sort Direction Indicators

function sortIcon(direction) {
    if (direction === 'asc') return '\u25B2';   // ▲
    if (direction === 'desc') return '\u25BC';   // ▼
    return '\u25C6';                             // ◆ (unsorted)
}

// Table header rendering
headers.forEach(h => {
    h.textContent = `${h.dataset.label} ${sortIcon(h.dataset.sort)}`;
});

Geometric Shapes Extended (U+1F780--U+1F7FF)

Unicode 7.0 added an extended block with additional geometric shapes:

These colored shapes render as emoji and provide a way to convey color information in text -- useful for game boards, status indicators, and category labels.

Font Support

Geometric shapes have excellent cross-platform support because they have been in Unicode since early versions:

For terminal and CLI applications, the block elements and basic geometric shapes are among the most reliably rendered characters across operating systems and terminal emulators, making them ideal for text-based user interfaces and data visualization.

Geometric shapes are workhorses of Unicode -- they appear in every rating widget, progress bar, sort indicator, and text-based chart on the modern web. The 96 characters in the primary Geometric Shapes block, combined with the 32 Block Elements and their extended counterparts, give developers a rich vocabulary for visual communication using nothing but plain text.