Answer:
Option D
Step-by-step explanation:
In the first three options we can evaluate the values of x with the help of Sine Rule for all the triangles
The Rule says

Where a , b and c are the sides opposite to the angles A, B and C of any ΔABC.
Hence , in order to determine unknown values of sides or angles , we need any 3 values from all 3 sides and 3 angles in a triangle. First Three options give us three values but the last option gives only 2.
Example
in first option we can apply Sine Rule as





Answer:
x=1/2; y=-6
Step-by-step explanation:
2x-2=-2x-5
4x=2
x=1/2
y=-1-5
y=-6
Answer:
Step-by-step explanation:
Comment
The formula that relates edges faces and vertices is F + V = E + 2
Givens
Edges (E): 37
Faces (F) = 25
Vertices: x
Solution
25 + x = 37 + 2 Subtract 25 from both sides.
25-25 +x= 37 - 25 + 2 Combine
x = 12 + 2
x = 14
Answer: The vertices =<u> 14</u>
20 because 10+10=20 and 20+20=40 and 20+40=60