/*! This file is auto-generated */ .wp-block-button__link{color:#fff;background-color:#32373c;border-radius:9999px;box-shadow:none;text-decoration:none;padding:calc(.667em + 2px) calc(1.333em + 2px);font-size:1.125em}.wp-block-file__button{background:#32373c;color:#fff;text-decoration:none} Problem 76 The longer leg of a right triang... [FREE SOLUTION] | 91Ó°ÊÓ

91Ó°ÊÓ

The longer leg of a right triangle is 4 feet longer than the other leg. Find the length of the two legs if the hypotenuse is 20 feet.

Short Answer

Expert verified
The legs are 12 feet and 16 feet long.

Step by step solution

01

Define Variables

Let\( x \) be the length of the shorter leg. Then the longer leg can be represented as\( x + 4 \). So, we have two legs: \( x \) and \( x + 4 \).
02

Apply the Pythagorean theorem

According to the Pythagorean theorem, for a right triangle with legs \( a \) and \( b \), and hypotenuse \( c \), the equation is \( a^2 + b^2 = c^2 \). Substituting our variables gives \( x^2 + (x + 4)^2 = 20^2 \).
03

Simplify the Equation

Expand and simplify the equation: \( x^2 + (x + 4)^2 = 400 \). This becomes \( x^2 + x^2 + 8x + 16 = 400 \), which simplifies to \( 2x^2 + 8x + 16 = 400 \).
04

Rearrange and Solve the Quadratic Equation

Rearrange the equation into standard form: \( 2x^2 + 8x + 16 - 400 = 0 \), which simplifies to \( 2x^2 + 8x - 384 = 0 \). Divide the entire equation by 2 to simplify: \( x^2 + 4x - 192 = 0 \). To solve for \( x \), use the quadratic formula \( x = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a} \), where \( a = 1 \), \( b = 4 \), and \( c = -192 \).
05

Calculate the Roots

Calculate the discriminant: \( b^2 - 4ac = 4^2 - 4 \times 1 \times (-192) = 16 + 768 = 784 \). Since the discriminant is positive, there are two real roots. Calculate them: \( x = \frac{-4 \pm \sqrt{784}}{2} \), which means \( x = \frac{-4 \pm 28}{2} \).
06

Determine Viable Solution

The two potential solutions for \( x \) are \( x = \frac{24}{2} = 12 \) and \( x = \frac{-32}{2} = -16 \). Since length cannot be negative, choose \( x = 12 \).
07

Verify Solution

With \( x = 12 \), the longer leg is \( x + 4 = 16 \). Verify using the Pythagorean theorem: \( 12^2 + 16^2 = 144 + 256 = 400 \), and the hypotenuse \( 20^2 = 400 \), confirming the solution is correct.

Unlock Step-by-Step Solutions & Ace Your Exams!

  • Full Textbook Solutions

    Get detailed explanations and key concepts

  • Unlimited Al creation

    Al flashcards, explanations, exams and more...

  • Ads-free access

    To over 500 millions flashcards

  • Money-back guarantee

    We refund you if you fail your exam.

Over 30 million students worldwide already upgrade their learning with 91Ó°ÊÓ!

Key Concepts

These are the key concepts you need to understand to accurately answer the question.

Pythagorean Theorem
The Pythagorean Theorem is a fundamental principle in geometry pertaining to right triangles. A right triangle possesses one angle measuring 90 degrees, known as the right angle. The theorem states that the square of the hypotenuse (the longest side opposite the right angle) is equal to the sum of the squares of the other two sides (the legs). This is mathematically expressed as:
  • For legs \( a \) and \( b \), and hypotenuse \( c \): \( a^2 + b^2 = c^2 \).
This theorem is useful for calculating the unknown lengths of a right triangle when the lengths of the other sides are known. In our specific problem, using the Pythagorean Theorem allows us to form an equation with the sides of the triangle expressed in terms of a single variable, which we can then solve to find the lengths of the sides.
Quadratic Equation
A quadratic equation is a second-degree polynomial equation that can be expressed in the standard form:
  • \( ax^2 + bx + c = 0 \)
where \( a \), \( b \), and \( c \) are constants, and \( x \) represents an unknown variable. In the process of solving a right triangle problem using the Pythagorean Theorem, a quadratic equation sometimes arises, especially when one of the triangle's legs is expressed as a function of the other. The quadratic formula allows us to find the value(s) of \( x \):
  • \( x = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a} \)
Understanding how to apply the quadratic formula is crucial in solving geometric problems involving right triangles where an equation is formed.
Length of Triangle Sides
Determining the length of a triangle's sides is a key skill in solving many geometry problems. For the right triangle, the length of each side is crucially interdependent with the others. Understanding the context of the problem allows us to express one side's length in terms of another variable. Let's recap how they were calculated here:
  • The shorter leg is assumed to be \( x \).
  • The longer leg was then formulated as \( x + 4 \);
  • Finally, using the equation derived from the Pythagorean Theorem, you can solve for \( x \), giving you both legs' lengths after substitution.
In this context, calculating the exact lengths is pivotal to ensure the correct application of the theorem.
Problem Solving in Geometry
Problem-solving in geometry often entails analyzing and understanding the relationships between different elements of a shape or figure, like angles and sides. Here, the problem requires identifying the relationship between the sides of a right triangle, using algebraic methods. To efficiently tackle a geometry problem:
  • Always start by understanding the properties of the figures involved.
  • Use known formulas, like the Pythagorean Theorem, to set up your equations.
  • Simplify and solve equations step-by-step, employing algebraic techniques as needed.
  • Develop a habit of verifying solutions to ensure they satisfy all equation conditions.
This ensures both accuracy and efficiency, attributes highly desirable when addressing geometry problems like the one we're dealing with in this example.

One App. One Place for Learning.

All the tools & learning materials you need for study success - in one app.

Get started for free

Most popular questions from this chapter

Multiply. See Section 5.4. $$ (x-4)(x+4) $$

The function \(f(x)=0.0007 x^{2}+0.24 x+7.98\) can be used to approximate the total cheese production in the United States from 2000 to \(2009,\) where \(x\) is the number of years after 2000 and \(y\) is pounds of cheese (in billions). Round answers to the nearest hundredth of a billion. (Source: National Agricultural Statistics Service, USDA) a. Approximate the number of pounds of cheese produced in the United States in 2000. b. Approximate the number of pounds of cheese produced in the United States in 2005. c. Use this function to estimate the pounds of cheese produced in the United States in 2015. d. From parts \((a),(b),\) and \((c),\) determine whether the number of pounds of cheese produced in the United States is increasing at a steady rate. Explain why or why not.

Factor each polynomial completely. See Examples 1 through 12. $$ 18 x^{4}+21 x^{3}+6 x^{2} $$

Explain how to convert a number from standard notation to scientific notation.

Recall that a graphing calculator may be used to check addition, subtraction, and multiplication of polynomials. In the same manner, a graphing calculator may be used to check factoring of polynomials in one variable. For example, to see that $$ 2 x^{3}-9 x^{2}-5 x=x(2 x+1)(x-5) $$ graph \(\mathrm{Y}_{1}=2 x^{3}-9 x^{2}-5 x\) and \(\mathrm{Y}_{2}=x(2 x+1)(x-5) .\) Then trace along both graphs to see that they coincide. Factor the following and use this method to check your results. $$ x^{3}+6 x^{2}+8 x $$

See all solutions

Recommended explanations on Math Textbooks

View all explanations

What do you think about this solution?

We value your feedback to improve our textbook solutions.

Study anywhere. Anytime. Across all devices.