diff --git a/libs/ui/include/psemek/ui/triangle_shape.hpp b/libs/ui/include/psemek/ui/triangle_shape.hpp
new file mode 100644
index 00000000..7a5253df
--- /dev/null
+++ b/libs/ui/include/psemek/ui/triangle_shape.hpp
@@ -0,0 +1,25 @@
+#pragma once
+
+#include <psemek/ui/shape.hpp>
+
+#include <psemek/geom/simplex.hpp>
+
+namespace psemek::ui
+{
+
+	struct triangle_shape
+		: shape
+	{
+		geom::triangle<geom::point<float, 2>> triangle{{{0.f, 0.f}, {0.f, 0.f}, {0.f, 0.f}}};
+
+		triangle_shape() = default;
+
+		triangle_shape(geom::triangle<geom::point<float, 2>> triangle)
+			: triangle{triangle}
+		{}
+
+		bool contains(geom::point<float, 2> const & point) const override;
+		geom::box<float, 2> bbox() const override;
+	};
+
+}
diff --git a/libs/ui/source/triangle_shape.cpp b/libs/ui/source/triangle_shape.cpp
new file mode 100644
index 00000000..22c87e65
--- /dev/null
+++ b/libs/ui/source/triangle_shape.cpp
@@ -0,0 +1,22 @@
+#include <psemek/ui/triangle_shape.hpp>
+
+#include <psemek/geom/contains.hpp>
+
+namespace psemek::ui
+{
+
+	bool triangle_shape::contains(geom::point<float, 2> const & point) const
+	{
+		return geom::contains(triangle, point);
+	}
+
+	geom::box<float, 2> triangle_shape::bbox() const
+	{
+		geom::box<float, 2> b;
+		b |= triangle[0];
+		b |= triangle[1];
+		b |= triangle[2];
+		return b;
+	}
+
+}