Big Ideas Math Geometry, 2014
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Big Ideas Math Geometry, 2014 View details
Cumulative Assessment

Exercise 5 Page 718

Use the Distance Formula.

Endpoints Length
J(-7, - 8) K(- 3,- 5) 5
C(- 4,2) D(1,4) ≈ 5.39
A(1,- 5) B(4,0) ≈ 5.83
G(- 1.5,0) H(4.5,0) 6
E(- 1,1) F(- 2,7) ≈ 6.08
L(10,- 2) M(9,6) ≈ 8.06
Practice makes perfect

We want to find the length of each line segment with the given endpoints. Then we will order the segments from shortest to longest.

Endpoints
A(1,- 5) B(4,0)
C(- 4,2) D(1,4)
E(- 1,1) F(- 2,7)
G(- 1.5,0) H(4.5,0)
J(-7, - 8) K(- 3,- 5)
L(10,- 2) M(9,6)
The length of a segment is the distance d between its endpoints (x_1, y_1) and (x_2,y_2). We can use the Distance Formula to find the lengths of each of the line segments. Let's recall the Distance Formula. d = sqrt((x_2-x_1)^2 + (y_2-y_1)^2) We will start with the first segment. The endpoints are A( 1, - 5) and B( 4, 0). Let's substitute these coordinates into the formula and evaluate.
sqrt((x_2-x_1)^2+(y_2-y_1)^2)
sqrt(( 4- 1)^2+( 0-( - 5))^2)
sqrt((4-1)^2+(0+5))^2)
sqrt(3^2+5^2)
sqrt(9+25)
sqrt(34)
5.830951...
5.83
The length of AB is approximately 5.83 units. Following similar steps, we will find the lengths of the remaining segments.
Endpoints Substitute Evaluate
A( 1, - 5) B( 4, 0) sqrt(( 4- 1)^2+( 0-( - 5))^2) ≈ 5.83
C( - 4, 2) D( 1, 4) sqrt(( 1-( - 4))^2+( 4- 2)^2) ≈ 5.39
E( - 1, 1) F( - 2, 7) sqrt(( - 2-( - 1))^2+( 7- 1)^2) ≈ 6.08
G( - 1.5, 0) H( 4.5, 0) sqrt(( 4.5-( - 1.5))^2+( 0- 0)^2) 6
J( - 7, - 8) K( - 3, - 5) sqrt(( - 3-( - 7))^2+( - 5-( - 8))^2) 5
L( 10, - 2) M( 9, 6) sqrt(( 9- 10)^2+( 6-( - 2))^2) ≈ 8.06

We can now order the segments from shortest to longest, where 1 is the shortest segment and 6 is the longest.

Endpoints Length Order
A(1,- 5) B(4,0) ≈ 5.83 3
C(- 4,2) D(1,4) ≈ 5.39 2
E(- 1,1) F(- 2,7) ≈ 6.08 5
G(- 1.5,0) H(4.5,0) 6 4
J(-7, - 8) K(- 3,- 5) 5 1
L(10,- 2) M(9,6) ≈ 8.06 6