Area of an Obtuse Triangle Calculator

If the basic triangle area formula is not enough, the area of an obtuse triangle calculator is made for you. Reading on, you'll find out:

• How to calculate the area of an obtuse triangle;
• What are the area of obtuse triangle formulas — for every occasion;
• How many types of obtuse triangles are there.

An obtuse triangle is a triangle with one interior angle greater than 90° (degrees).

The characteristics of an obtuse triangle are:

• One interior angle is greater than 90° (90 degrees being a right angle);
• The rest of the angles are under 90° (acute angles);
• The side opposite the obtuse angle is the longest side of the triangle;
• Can be a scalene or an isosceles triangle, but can never be an equilateral triangle.

To use our obtuse triangle calculator:

1. Determine which data you have given in your math task.

2. Choose the mode that you want to use — it depends on what you already know.

   • Let's assume we know the length of two sides and an angle between them. We have to choose the SAS mode.

3. Input the length of the sides and a measure of the angle between them. You can choose the units for the most convenient for you and switch them at any time.

4. The result appears immediately in the last row of the calculator.

5. If you want to change the mode, choose another one from the drop-down list — no need to restart the calculator.

6. Now you know how to use the area of an obtuse triangle calculator!

There are four ways to find the area of an obtuse triangle. Which you use depends on which data you have given. You can calculate the area of an obtuse triangle with sides and angles, with sides only, or with the height and base.

The area of obtuse triangle formulas based on what data is known are as follows:

1. Base ($b$) and height ($h$)

2. Three sides ($a$, $b$, $c$)

3. Two sides and the angle between them (sides $a$ and $b$ and angle $\gamma$)

4. Two angles ($\gamma$ and $\beta$) and a side between them ($a$)

Check out the rest of our triangle area calculators collection:

• Triangle area calculator;
• Similar triangles calculator;
• 3 sides triangle area calculator;
• Square feet of a triangle calculator;
• Scalene triangle area calculator;
• Area of oblique triangle calculator;
• Area of triangle with coordinates calculator; and
• Area of triangle SAS calculator.

The area of this triangle is 61.19 in². To find the triangle area with three sides:

1. Use Heron's formula:
   area = 0.25 × √[(a + b + c)(−a + b + c)(a − b + c)(a + b − c)]
2. Knowing all three a, b, and c, we can solve the equation, and realize that...
3. The answer is 61.19 in².

To count the area with two sides and an angle between them, use the formula:

• area = 0.5 × a × b × sin(γ), where a, b are the sides and γ is the angle between those sides.

To calculate the area with two angles and a side between them, use the equation:

• area = a² × sin(β) × sin(γ) / [2 × sin(β + γ)], where β and γ are the angles, and a is the side between those angles.

There are two main types of obtuse triangles:

• Isosceles — with two sides equal;
• Scalene — with no sides equal.

The area of this triangle is 62.14 in². To calculate it step by step:

1. Use the formula area = a² × sin(β) × sin(γ) / [2 × sin(β+γ)], where β and γ are the angles, and a is the side between those angles.
2. Solve the equation: area = 13² × sin(97) × sin(34) / [2 × sin(97+34)].
3. The area of this triangle is 62.14 in².