1,2,4belong on company sources and 3 should be on external information
Answer:
B
Step-by-step explanation:
Euler's formula for polyhedra states that
F + V - E = 2
where F is faces, V is vertices and E is edges
Substitute the values given and solve for F, that is
F + 13 - 26 = 2
F - 13 = 2 ( add 13 to both sides )
F = 15 → B
Answer:
C
Step-by-step explanation:
∠ AFD = ∠ AFB + ∠ BFC + ∠ CFD
The 3 angles form a straight angle and sum to 180°, that is
4x + 5 + 6x + 3 + 5x + 7 = 180, that is
15x + 15 = 180 ( subtract 15 from both sides )
15x = 165 ( divide both sides by 15 )
x = 11
∠ CFD = 5x + 7 = 5(11) + 7 = 55 + 7 = 62°, thus
∠ AFE = ∠ CFD = 62° ( vertical angles are congruent )