Plz answer the question is on the picture

you : )

The increase of pollutants from in mexico has raised concerns about garage to health and the environment

Geologists know that potassium-40 decays to argon-40, with a half-life of 1.3 billion years. if an analysis of a feldspar crystal in a sample of granite shows that 75 percent of the potassium-40 atoms have decayed to form argon-40, what is the age of the granite

The blue segment below is a diameter of oo. what is the length of the radius of the circle?