Re: vertices of a rectangle
- To: mathgroup at smc.vnet.net
- Subject: [mg131276] Re: vertices of a rectangle
- From: Tomas Garza <tgarza10 at msn.com>
- Date: Sun, 23 Jun 2013 22:55:58 -0400 (EDT)
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Uppercase letters are reserved for Mathematica's own symbols. So, if your four points are In[1]:= {a = {1, 4}, b = {7, 0}, c = {5, -3}, d = {-1, 1}} Out[1]= {{1, 4}, {7, 0}, {5, -3}, {-1, 1}} Show, first, that the vectors a-d and b-c are parallel: In[2]:= VectorAngle[a - d, b - c] Out[2]= 0 and so are the vectors b-a and c-d: In[3]:= VectorAngle[b - a, c - d] Out[3]= 0 Any two adjoining sides are orthogonal: In[4]:= VectorAngle[a - d, b - a] Out[4]= Pi/2 Check that the parallel sides have the same length, so the four points determine a rectangle. In[5]:= EuclideanDistance[d, a] == EuclideanDistance[c, b] Out[5]= True In[6]:= EuclideanDistance[b, a] == EuclideanDistance[c, d] Out[6]= True Determine the length of the sides In[7]:= d1 = EuclideanDistance[d, a] Out[7]= Sqrt[13] In[8]:= d2 = EuclideanDistance[b, a] Out[8]= 2 Sqrt[13] The area of the rectangle is In[9]:= d1 d2 Out[9]= 26 -Tomas > From: clariceane16 at yahoo.com > Subject: vertices of a rectangle > To: mathgroup at smc.vnet.net > Date: Sat, 22 Jun 2013 20:46:28 -0400 > > need help for this :)) > > show that the points A=(1,4), B=(7,0), C=(5,-3), D=(-1,1) are the vertices of the rectangle, find it's area. >
- References:
- vertices of a rectangle
- From: clarice <clariceane16@yahoo.com>
- vertices of a rectangle