(box: x-ray)  (F: faces)  (slider: perspective)  (image: L=rotate R=zoom)  (M: metrics)

Elongated Pentagonal Diypramid
canonical form
Vertices:  12  (10[4] + 2[5])
Faces:15  (10 isosceles triangles + 5 squares)
Edges:25  (10 short + 15 long)
Symmetry:  5-fold Prismatic  (D5h)
Dual Solid:  Pentagonal Bifrustum
(values below based on edge-scribed radius = 1)
Short Edge (10):  sqrt(10*(185+11*sqrt(5)))/40    ≈1.1445434344982764968
Long Edge (15):  sqrt(2*(5−sqrt(5)))/2    ≈1.1755705045849462583
Edge-scribed Radius:  1
Volume:5*(2+7*sqrt(5))/24    ≈3.6775991338538599739