Answer:
C. 10
Step-by-step explanation:
we know that
The height of an isosceles triangle divide the triangle into two equal right triangles.
so
Applying the Pythagorean Theorem at one triangle
[tex]13^2=(x+7)^2+(2x/2)^2[/tex]
solve for x
[tex]169=x^2+14x+49+x^2[/tex]
[tex]2x^2+14x-120=0[/tex]
solve the quadratic equation by graphing
using a graphing tool
The solution is x=5
see the attached figure
therefore
The length of the base is
[tex]2(5)=10\ units[/tex]
