The image contains three mathematical problems involving geometry. Here are the details:

1. Problem 42:

   • The problem asks you to find the length of the sides $BC$ and $AD$ of a quadrilateral $ABCD$ given that $AB$ is parallel to $CD$, and the diagonals $AC$ and $BD$ are equal.

2. Problem 43:

   • This problem involves a figure labeled $ABCD$ with a marked diagonal and some angles. The task is likely to involve solving for angles or verifying certain properties about the quadrilateral based on the given diagram.

3. Problem 44:

   • Part (a) asks to find the size of each exterior angle of a regular 15-sided polygon.
   • Part (b) asks to calculate the number of sides of a regular polygon where each exterior angle is 15 degrees.

Would you like to explore the solutions for all these problems, or is there a specific problem you'd like to focus on first?