Table of contents
- 0. Review of College Algebra4h 43m
- 1. Measuring Angles39m
- 2. Trigonometric Functions on Right Triangles2h 5m
- 3. Unit Circle1h 19m
- 4. Graphing Trigonometric Functions1h 19m
- 5. Inverse Trigonometric Functions and Basic Trigonometric Equations1h 41m
- 6. Trigonometric Identities and More Equations2h 34m
- 7. Non-Right Triangles1h 38m
- 8. Vectors2h 25m
- 9. Polar Equations2h 5m
- 10. Parametric Equations1h 6m
- 11. Graphing Complex Numbers1h 7m
7. Non-Right Triangles
Law of Cosines
4:54 minutes
Problem 27
Textbook Question
Textbook QuestionIn Exercises 25–30, use Heron's formula to find the area of each triangle. Round to the nearest square unit. a = 14 meters, b = 12 meters, c = 4 meters
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Key Concepts
Here are the essential concepts you must grasp in order to answer the question correctly.
Heron's Formula
Heron's formula is a method for calculating the area of a triangle when the lengths of all three sides are known. It states that the area can be found using the formula A = √(s(s-a)(s-b)(s-c)), where 's' is the semi-perimeter of the triangle, calculated as s = (a + b + c) / 2. This formula is particularly useful when the height of the triangle is not known.
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Semi-perimeter
The semi-perimeter of a triangle is half of its perimeter and is denoted by 's'. It is calculated by adding the lengths of all three sides and dividing by two: s = (a + b + c) / 2. The semi-perimeter is a crucial component in Heron's formula, as it helps simplify the calculation of the area by providing a reference point for the side lengths.
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Triangle Inequality Theorem
The Triangle Inequality Theorem states that for any triangle, the sum of the lengths of any two sides must be greater than the length of the third side. This theorem is essential for determining whether a set of three lengths can form a triangle. In the given problem, verifying that a = 14 m, b = 12 m, and c = 4 m satisfy this theorem ensures that the area calculated using Heron's formula is valid.
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