Area of any triangle.
Master the art of finding the area of any triangle—whether acute, obtuse, or isosceles. Use the perpendicular height and base to conquer these measurement challenges!

🙂 = Correct, ☹️ = Incorrect

📌 Rules

• Use the general area formula for all triangles:Area = (base × perpendicular height) ÷ 2 (or 1/2 × b × h).

• Identify the perpendicular height: The height MUST be the straight line that meets the chosen base at a 90° right angle, measuring from the base straight up to the opposite point (vertex).

💡 Tips

• Halve an even number first: If either the base or the perpendicular height is an even number, halve it before multiplying to simplify your calculation (e.g. for a base of 12 cm and height of 5 cm: calculate 6 × 5 = 30 cm²).

• Height for obtuse triangles: In an obtuse-angled triangle, the perpendicular height is often drawn as a dashed line outside the triangle to show the vertical height from the base line—use this height with the original base length only.

• Quick typing on our platform: Typing your answer is designed to be super quick and simple! Just type plain digits or decimals like 30 or 14.5 without adding unit labels (e.g. cm, cm², m²) or extra spaces.

⚠️ Warnings

• Do not use slanted side lengths as the height: The height is never a diagonal or slanted side unless it explicitly meets the base at 90°. Ignore extra slanted side measurements given in diagrams!

• Always remember to divide by 2: Multiplying base × height gives the area of a rectangle or parallelogram, so you must divide by 2 to get the triangle’s area.