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put this solution on YOUR website!isosceles means that the two base angles are equal as are the sides opposite the angles
LW=TW __ 7X+21=4X+21 __ subtracting 4x+21 __ 3X=0 __ X=0
LW=TW=21
there are 180º in a triangle __ the vertex angle is 90º, so the sum of the two base angles is also 90º
__ so each bse angle equals 45º
by Pythagoras __ LT^2=LW^2+TW^2 __ LT^2=2(21^2) __ LT=21*sqrt(2)