Hope these help but i wrote all of it out with all its geometrical reasons
The period will be the length for one cycle of the function.
answer: 10
The negative sign show the change in direction, that is the opposite side of the value.
In the number line, 1 is the opposite of -1, that is the digit from the left side is the opposite value of the right side.
Consider an object P is moving in positive x direction than on moving the object into its opposite direction, it will move along the negative x axis.
Answer : A) -
The answer is Rhombus because it is two equilateral triangles that can create a quadrilateral. A quadrilateral has exactly four sides and it is also a polygon. A rhombus has four equal sides and it is any parallelogram with equal sides including a square. A rhombus is like a diamond. In your question, the craft project that has a two equilateral triangle that tapes together and creates an equilateral, I picture it as a diamond and the diamond is including in the family of a rhombus. All side have equal length, opposite side is parallel and the other opposite angles are equal.
