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Archaeologists attempt to reconstruct past ways of life by examining preserved bones, the ruins of buildings, and artifacts such as tools, pottery, and jewelry.

 

During an archaeological dig, a coordinate grid is laid over the site to identify the location of artifacts as they are excavated.  During a dig, three corners of a triangular building have been partially unearthed at (-1, 6), (4, 5), and (-3, -4). 

 

If each square on the grid measures one square foot, estimate the area of the floor of the building.

 

















a.


about 50ft 2


c.


about 10ft 2


b.


about 26ft 2


d.


about 70ft 2

 Nov 17, 2014

Best Answer 

 #1
avatar+23254 
+5

A = (-1, 6)         B = (4, 5)         C = (-3, -4)

Use the distance formula to find the distance of each side:  d  =  √[ (x2 - x1)² + (y2 - y1)² ]

AB:  (x1, y1) = (-1, 6)         (x2, y2) = (4, 5)     --->  d  =  √[ (4 - -1)² + (5 - 6)² ]  

       --->   d  =  √[ (5)² + (-1)² ]     --->   d  =  √( 25 + 1)     --->     d  =  √26

BC:  (x1, y1) = (4, 5)         (x2, y2) = (-3, -4)     --->  d  =  √[ (-3 - 4)² + (-4 - 5)² ]  

       --->   d  =  √[ (-7)² + (-9)² ]     --->   d  =  √( 49 + 81)     --->     d  =  √130

AC:  (x1, y1) = (-1, 6)         (x2, y2) = (-3, -4)     --->  d  =  √[ (-3 - -1)² + (-4 - 6)² ]  

       --->   d  =  √[ (-2)² + (-10)² ]     --->   d  =  √( 4 + 100)     --->     d  =  √104

Since AB² + AC²  =  BC², this is a right triangle with sides AB and AC.

To find the area:  Area  =  ½ · AB · AC  =  ½ · √26 · √104 =  ½ · √2704  =  ½ · 52  =  26

 Nov 18, 2014
 #1
avatar+23254 
+5
Best Answer

A = (-1, 6)         B = (4, 5)         C = (-3, -4)

Use the distance formula to find the distance of each side:  d  =  √[ (x2 - x1)² + (y2 - y1)² ]

AB:  (x1, y1) = (-1, 6)         (x2, y2) = (4, 5)     --->  d  =  √[ (4 - -1)² + (5 - 6)² ]  

       --->   d  =  √[ (5)² + (-1)² ]     --->   d  =  √( 25 + 1)     --->     d  =  √26

BC:  (x1, y1) = (4, 5)         (x2, y2) = (-3, -4)     --->  d  =  √[ (-3 - 4)² + (-4 - 5)² ]  

       --->   d  =  √[ (-7)² + (-9)² ]     --->   d  =  √( 49 + 81)     --->     d  =  √130

AC:  (x1, y1) = (-1, 6)         (x2, y2) = (-3, -4)     --->  d  =  √[ (-3 - -1)² + (-4 - 6)² ]  

       --->   d  =  √[ (-2)² + (-10)² ]     --->   d  =  √( 4 + 100)     --->     d  =  √104

Since AB² + AC²  =  BC², this is a right triangle with sides AB and AC.

To find the area:  Area  =  ½ · AB · AC  =  ½ · √26 · √104 =  ½ · √2704  =  ½ · 52  =  26

geno3141 Nov 18, 2014

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