Answer:
? = 10
Explanation:
the triangle has 2 congruent sides and is therefore isosceles.
the segment from the vertex to the bas is a perpendicular bisector splitting the triangle into 2 right triangles.
Consider the right triangle on the left with legs 6 and 8 and hypotenuse ?
using Pythagoras' identity in the right triangle , then
?² = 6² + 8² = 36 + 64 = 100 ( take square root of both sides )
? =
= 10