The coordinates of the vertices of BEA are B(1,2), E(-5,3), and A(-6,-3). Prove that BEA is isosceles. State the coordinates of point R such that quadrilateral BEAR is a square. Prove that your quadrilateral BEAR is a square.

Step-by-step explanation:

New Note 2

Given coordinates:

B(1,2)

E(-5,3)

A(-6,3)

Part A, isosceles triangle

Need to find lengths of sides

BE^2 = ((-5-1)^2+(3-2)^2) = 36+1 = 37

BA^2 = ((-6-1)^2+(-3-2)^2) = 49+25 = 74

EA^2 = ((-6-(-5))^2+(-3-3)^2) = 1+ 36 = 37

Since BE^2 = EA^2, BE=EA, or triangle BEA is isosceles, with vertex at E.

Part B, find point R so that BEAR is a sqare

Need to show that the vertex angle, BEA is a right angle.

BA is diagonal and E is 90° if

BE^2 + EA^2 = BA^2

or

37+37 = 74

Hence angle BEA is right anglesd, and the two legs are eaual with length sqrt(37)

To find point R, we find the translation from point E to point B, i.e. from the vertex to end of one of the legs.

EB = B - E = (1-(-5))-(2-3) = <6,-1>

To find point R, apply this translation to the end of the other leg, i.e. point A,

R=A(-6,-3) + <6,-1>=R(0,-4)

Check:

RE (diagonal)^2 = ((0-(-5))^2+(-4-3)^2)  = 25+49 = 74 checks

RB^2 = ((0-1))^2+(-4-2)^2)  = 1+36 = 37 checks

RA^2 = ((0--(-6))^2+(-4-(-3))^2)  = 36+1 = 37 checks

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step-by-step explanation: