Asolid has faces that consist of 5 congruent squares and 4 congruent equilateral triangles. the solid has 9 vertices. how many edges does the solid have

16 edges because,
f(faces) + v(vertices) - e(edges) = 2,

so we should know that,
that f = 5 + 4 = 9
and v = 9
but we dont know what equals e

So this is what i did: f + v - e = 2
so then 9 + 9 - e = 2
then 18 - e = 2
and 18 = e + 2
then you subtract e = 18 - 2
and it should e should = 16
I hope this helped ^-^