The image includes two exercises related to geometry.

1. Exercise 1:

   • This exercise explains the formula for finding the area of a rhombus.
   • Instructions are given as follows:
     • Step 1: Multiply together the lengths of the two diagonals.
     • Step 2: Divide by 2.
   • The task is to find a formula for the area, $A$ (in square centimeters), of a rhombus with diagonals of lengths $t$ cm and $u$ cm.

   The formula for the area $A$ of a rhombus with diagonals $t$ and $u$ is: $A = \frac{t \cdot u}{2}$

2. Exercise 2:

   • The diagram shows an isosceles triangle.
   • The task is to find a formula for $y$ in terms of $x$.

   Since the diagram isn’t entirely clear in the image, I’ll assume it's a standard isosceles triangle configuration. Generally, in an isosceles triangle, if the lengths and angles are given, there may be trigonometric relationships or properties of congruent sides and angles that relate $y$ and $x$. If the problem involves using height or specific trigonometric properties, those would provide a specific formula.

If you’d like, please confirm if any particular details in the diagram are visible so I can offer more precise help on finding $y$ in terms of $x$.

Would you like further details or have any questions?

Here are related questions you might find interesting:

1. What are the properties of a rhombus and how do they relate to its area?
2. How is the formula for the area of a rhombus derived?
3. Can we find the area of a rhombus if only one diagonal is given?
4. What are the properties of an isosceles triangle?
5. How do trigonometric functions relate the sides and angles in an isosceles triangle?

Tip: In geometry, understanding the properties of shapes helps in deriving and remembering area and perimeter formulas.