Angle Symbol ∠ and Geometry Symbols: Copy and Type

Geometry Symbols Table: Angle Symbol in Maths and More

The symbol of angle (∠) is different from the less-than sign (<). ∠ has a flat bottom line, while < is two lines meeting at a point. See the less than symbol page if you mix them up.

Perpendicular Symbol ⊥ and Parallel Symbol ∥

The perpendicular symbol ⊥ is an upside-down T. It shows that two lines cross at a right angle. In a proof you might write: "∵ OD ⊥ AB, ∴ ∠ODA = 90°."

The parallel symbol ∥ is two vertical lines. Writing PQ ∥ RS means the two lines run side by side and never meet. A line through both, called a transversal, makes equal alternate angles.

Do not use the keyboard key | twice (||) in a typed report if you can avoid it. It looks similar but is a programming sign, while ∥ is the proper geometry character. In Word, type 2225 then Alt+X for ∥ and 22A5 then Alt+X for ⊥.

Triangle Symbol and Congruence Symbol

The triangle symbol △ comes before three capital letters: △ABC. It is a hollow (white) triangle; the solid ▲ is used for decoration and bullet points, not in geometry. An inverted triangle ▽ is a different shape and in maths ∇ means the del operator.

The symbol of congruence, ≅, is an equals sign with a wave on top. It means two figures match exactly in size and shape. The rules students learn in Class 9, SSS, SAS, ASA, RHS and AAS, are what you write as the reason, for example "∴ △ABD ≅ △ACD (SAS)". The similar sign ∼ is just the wave, used when figures have the same shape but different sizes.

Need a triangle symbol text version for a bio or a heading? Copy △ or ▲ from our cool symbols page. The coloured warning triangle is on the warning symbols page.

How to Type Angle Symbol in Word

The angle symbol has no Alt code or Mac Option key, so these are the ways to type it:

1. Code and Alt+X (Windows Word): type 2220 and press Alt+X. This is the closest thing to a shortcut key for the angle symbol in Word.
2. Equation editor: press Alt+= to open a new equation, type \angle and press Space.
3. Insert > Symbol: Insert tab, Symbol, More Symbols. Choose the font Cambria Math, and in the Subset list pick Mathematical Operators. Click ∠ and Insert.
4. Copy and paste from this page.

In Google Docs use Insert > Special characters and search "angle". On a Mac press Control+Command+Space and search. On a phone, the angle symbol in keyboard layouts is missing, so copy it from here. The degree symbol page covers ° in full.

Line Symbols: Straight Line, Ray and Segment

In geometry, the straight line symbol is not a separate character. It is a mark drawn over two letters:

In typed work, you can write "line AB", "ray AB" or "segment AB" if your software cannot place marks on top. For a plain horizontal line symbol in text, characters like ─ or ⎯ are used for drawing, and the dash symbol and hyphen symbol pages explain the shorter dashes.

1st Angle and 3rd Angle Symbol in Engineering Drawing

In engineering drawing, "angle" also means the projection method. The 1st angle and 3rd angle symbol is a small drawing of a truncated cone shown in two views: a trapezium and two circles.

• 1st angle projection: the circles are drawn to the right of the trapezium. This method is commonly taught in Indian engineering drawing courses.
• 3rd angle projection: the circles are drawn to the left of the trapezium.

These symbols are drawings placed in the title block, not text characters, so there is no Unicode code for them. For tolerance signs on drawings, see our GD&T symbols chart and the diameter symbol page.