Two corners of an isosceles triangle are at (8 ,3 ) and (6 ,2 ). If the triangle's area is 4 , what are the lengths of the triangle's sides?

1 Answer
Jan 19, 2018

Three sides of the he isosceles triangle are color(blue)(2.2361, 2, 2)

Explanation:

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a = sqrt((6-8)^2 + (2-3)^2) = 2.2361

h =(2* Area) / a = (2*4)/2.2361 = 3.5777

Slope of base BC m_a = (2-3) / (6-8) = 1/2

Slope of altitude AD is -(1/m_a) = -2

Midpoint of BC D = (8+6)/2, (3+2)/2 = (7, 2.5)

Equation of AD is

y - 2.5 = -2 * (x - 7)

y + 2x = 11.5 Eqn (1)

Slope of BA =m_b =tan theta = h / (a/2) = (2 * 3.5777) / 2.2361 = 3.1991

Equation of AB is

y - 3 = 3.1991 * (x - 8)

y - 3.1991x = - 22.5928 Eqn (2)

Solving Eqns (1), (2) we get the coordinates of A

A (6.5574, 1.6149)

Length AB =c = sqrt((8-6.5574)^2 + (3-1.6149)^2) = 2

Three sides of the he isosceles triangle are color(blue)(2.2361, 2, 2)