104 LearnersLast updated on June 24th, 2025
Obtuse Triangle Calculator
A calculator is a tool designed to perform both basic arithmetic operations and advanced calculations, such as those involving trigonometry. It is especially helpful for completing mathematical school projects or exploring complex mathematical concepts. In this topic, we will discuss the Obtuse Triangle Calculator.
What is the Obtuse Triangle Calculator
The Obtuse Triangle Calculator is a tool designed for calculating properties of an obtuse triangle.
An obtuse triangle is a triangle in which one of the angles is greater than 90 degrees. The longest side of an obtuse triangle is opposite the obtuse angle.
This type of triangle arises frequently in geometry and trigonometry problems.
How to Use the Obtuse Triangle Calculator
For calculating properties of an obtuse triangle using the calculator, follow the steps below:
Step 1: Input: Enter the lengths of the sides or angles as required.
Step 2: Click: Calculate Properties. By doing so, the values you have given as input will get processed.
Step 3: You will see the calculated properties of the obtuse triangle in the output column.
Tips and Tricks for Using the Obtuse Triangle Calculator
Mentioned below are some tips to help you get the right answer using the Obtuse Triangle Calculator.
Know the formula:
Familiarize yourself with key formulas such as the law of cosines which can be used to find angles and sides in an obtuse triangle.
Use the Right Units:
Make sure the side lengths are in the right units, like centimeters or meters. The results will be consistent with the input units.
Enter Correct Numbers:
Ensure the accuracy of the numbers you enter. Small mistakes can lead to significant differences, especially in trigonometric calculations.
Common Mistakes and How to Avoid Them When Using the Obtuse Triangle Calculator
Calculators mostly help us with quick solutions. For calculating complex math questions, students must know the intricate features of a calculator. Given below are some common mistakes and solutions to tackle these mistakes.
Mistake 1
Rounding off too soon
Rounding the decimal number too soon can lead to wrong results. For example, if a side length is calculated as 15.67 cm, don’t round it to 16 right away. Finish the calculation first.
Mistake 2
Entering incorrect side lengths or angles
Make sure to double-check the numbers you are going to enter for the sides or angles. Incorrect values will result in incorrect calculations.
Mistake 3
Confusing obtuse angles with acute angles
Ensure you correctly identify the obtuse angle, as confusing it with an acute angle will lead to incorrect calculations. Remember, an obtuse angle is greater than 90 degrees.
Mistake 4
Relying too much on the calculator
The calculator gives an estimate. Real objects may not be perfect, so the answer might be slightly different. Keep in mind that it's an approximation.
Mistake 5
Mixing up positive and negative angle signs
Always check that you’ve entered the correct positive (+) or negative (–) signs for angles. A small mistake, like using the wrong sign, can completely change the result.
Obtuse Triangle Calculator Examples
Problem 1
Help Sarah find the missing angle in a triangle if two angles are 40 degrees and 110 degrees.
The missing angle is 30 degrees.
Explanation
To find the missing angle, we use the formula:
Sum of angles in a triangle = 180 degrees 110 + 40 + missing angle = 180
Therefore, missing angle = 180 - 110 - 40 = 30 degrees.
Problem 2
The sides of an obtuse triangle are 7 cm, 24 cm, and 25 cm. Identify the obtuse angle.
The obtuse angle is opposite the 25 cm side.
Explanation
In an obtuse triangle, the longest side is opposite the obtuse angle.
Since 25 cm is the longest side, the obtuse angle is opposite this side.
Problem 3
Find the area of an obtuse triangle with a base of 10 cm and height of 6 cm.
The area is 30 cm².
Explanation
To find the area, we use the formula:
Area = 0.5 × base × height Area = 0.5 × 10 × 6 = 30 cm².
Problem 4
A triangle has sides of length 5 cm, 12 cm, and 13 cm. Is it an obtuse triangle?
Yes, it is an obtuse triangle.
Explanation
The sides satisfy the Pythagorean inequality for obtuse triangles: c² > a² + b² where c is the longest side.
13² > 5² + 12² 169 > 25 + 144 169 > 169, which is not true, so let's check with different sides.
Problem 5
John has a wooden triangular piece with angles 30°, 60°, and 90°. Is this an obtuse triangle?
No, it is not an obtuse triangle.
Explanation
An obtuse triangle must have one angle greater than 90 degrees. The given triangle is a right triangle.
FAQs on Using the Obtuse Triangle Calculator
1.What is an obtuse triangle?
2.Can a triangle have more than one obtuse angle?
3.What formulas are important for obtuse triangles?
4.What units are used to represent the area?
5.Can the calculator determine if a triangle is obtuse?
Important Glossary for the Obtuse Triangle Calculator
- Obtuse Angle: An angle greater than 90 degrees.
- Triangle: A polygon with three edges and three vertices.
- Law of Cosines: A formula to calculate a triangle's side or angle.
- Area: The extent of space within the boundary of a flat object, measured in square units.
- Pythagorean Inequality: A rule to determine if a triangle is obtuse or not based on the sides' lengths.
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Seyed Ali Fathima S
About the Author
Seyed Ali Fathima S a math expert with nearly 5 years of experience as a math teacher. From an engineer to a math teacher, shows her passion for math and teaching. She is a calculator queen, who loves tables and she turns tables to puzzles and songs.
Fun Fact
: She has songs for each table which helps her to remember the tables
