Answer:
RA = 24
Step-by-step explanation:
Since the triangle is isosceles ( 2 equal sides ) , then LU is a perpendicular bisector , so
AU = RU , that is
4r = 18 - 2r ( add 2r to both sides )
6r = 18 ( divide both sides by 6 )
r = 3
Then
RA = 18 - 2r + 4r = 18 + 2r = 18 + 2(3) = 18 + 6 = 24
