Evaluate the length of the line KL where K(a,0) and L ...

Pls , the question is in the picture!

The diameter of a circular chip is doubled to use in a new board game. the area of the new chip will be

Acompany that manufactures and sells guitars made changes in their product range. from the start they had 20 models. then they reduced the number of models to 15. as a result, the company enjoyed a 10% increase in turnover. - how much did the stock level change? in (%)