notice the points given form a horizontal line, so the length of the side must be 7
the x coordinate of the third point must be midway between the two points (simple geometry, look at your sketch)
let the third point be P
P is (-3/2, y)
so the distance from P to (2,3) must be 7
√(2 + 3/2)^2 + (y-3)^2 = 7
√( 49/4 + (y-3)^2) = 7
square both sides
49/4 + (y-3)^2 = 49
(y-3)^2 = 147/4
y-3 = ± √147/2
y = 3 ± √147/2 or (6 ± √147)/2
There is a point above the base and it is (-3/2 , (6+√147)/2 )
and one below which is (-3/2 , 6 -√147)/2 )
The two vertices that form the base of an isosceles triangle are (-5, 3) and (2, 3). What are the coordinates of the other vertex?
1 answer