Answer:
Correct option: third one -> 12
Step-by-step explanation:
In a polygon with 'n' vertex, we can trace diagonals from one vertex to all vertices, except to the vertex chosen and the two adjacent vertices (because we would have sides and not diagonals), so we would have 'n - 3' diagonals.
If we have a polygon with 15 vertex, the number of diagonals from one vertex is 15 - 3 = 12.
Correct option: third one
The number would be 21 because if you add 5+37 then divide by 2.Younwill get the answer
Answer:

Step-by-step explanation:
Area of a rhombus is the product of the length of the diagonals divided by two.
Length of one diagonal is 8 units and the other diagonal is 16 units
Area is given by

The area of the rhombus is 
Another approach is the diagonals have created 4 triangles where the base and is height is either 4 units long or 8 units long so the area of the rhombus would be the area of the 4 triangles.

The relationship for this function is linear love
10% as a decimal is 0.10
Hope this helps!