Question

Difficulty: EasyPythagorean Theorem and Special Right Triangles

A rectangular garden has a straight walking path that connects two opposite corners. The length of the path is 170170 meters, and the width of the garden is 8080 meters. What is the length, in meters, of the garden?

  1. A
    90
  2. B
    120
  3. 150Answer
  4. D
    188
  5. E
    250

Answer

The length of the garden is 150150 meters.
The diagonal path, width, and length of the rectangular garden form a right triangle where the path is the hypotenuse. According to the Pythagorean theorem, the square of the length plus the square of the width equals the square of the path: length2+802=1702\text{length}^2 + 80^2 = 170^2. This simplifies to length2+6,400=28,900\text{length}^2 + 6,400 = 28,900. Subtracting 6,4006,400 from both sides gives length2=22,500\text{length}^2 = 22,500. Taking the square root of 22,50022,500 yields 150150 meters.

Step-by-Step Solution

1
Identify the right triangle formed by the length, width, and diagonal path of the garden.
The width (8080 meters) and the unknown length are the legs, while the diagonal path (170170 meters) is the hypotenuse.
The diagonal of a rectangle forms two congruent right triangles with the rectangle's sides.
2
Set up the Pythagorean equation to solve for the unknown leg.
length2+802=1702\text{length}^2 + 80^2 = 170^2
The Pythagorean theorem states that a2+b2=c2a^2 + b^2 = c^2, where cc is the hypotenuse.
3
Calculate the squares of the known lengths.
802=6,40080^2 = 6,400 and 1702=28,900170^2 = 28,900
Evaluate the exponents to simplify the equation.
4
Isolate the squared unknown variable.
length2=28,9006,400=22,500\text{length}^2 = 28,900 - 6,400 = 22,500
Subtract 6,4006,400 from both sides of the equation.
5
Take the square root of both sides to find the length.
length=22,500=150\text{length} = \sqrt{22,500} = 150
The square root operation reverses the squaring of the variable.

Key Concept

Applying the Pythagorean theorem to find the length of an unknown leg in a right triangle.
Estimated Time:1m 0s
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