A is not a line of symmetry
Answer:
102.3
Step-by-step explanation:
a_38 = -5
difference d= -2.9
We use general formula

WE make the formula for a_38 th term
Plug in 38 for n

Now plug in -2.9 for d and -5 for a_38


Now add 107.3 on both sides
102.3 = a_1
option A is correct
Answer:
25
Step-by-step explanation:
You have to do base x height divided by 2
50/2
Answer:
m∠CFD is 70°
Step-by-step explanation:
In the rhombus
- Diagonals bisect the vertex angles
- Every two adjacent angles are supplementary (their sum 180°)
Let us solve the question
∵ CDEF is a rhombus
∵ ∠E and ∠F are adjacent angles
→ By using the second property above
∴ ∠E and ∠F are supplementary
∵ The sum of the measures of the supplementary angles is 180°
∴ m∠E + m∠F = 180°
∵ m∠E = 40°
∴ 40° + m∠F = 180°
→ Subtract 40 from both sides
∵ 40 - 40 + m∠F = 180 - 40
∴ m∠F = 140°
∵ FD is a diagonal of the rhombus
→ By using the first property above
∴ FD bisects ∠F
→ That means FD divides ∠F into 2 equal angles
∴ m∠CFD = m∠EFD =
m∠F
∴ m∠CFD =
(140°)
∴ m∠CFD = 70°