Question 363510
Let a=the common altitude of each triangle.
a^2+b^2=c^2
a^2+10^2=x^2 for one of the triangles.
a^2=x^2-100
a=sqrt(x^2-100)
.
0.5ab=A(triangle)
0.5*10(sqrt(x^2-100))
=5*sqrt(x^2-100) area of one of the triangles.
10*sqrt(x^2-100) area of the triangles together.
.
Ed