In what states might people work at a ski resort

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 physical processes that create most of earth's physical features, including mountains, are known as

In the diagram below, ab and bc are tangent to o. what is the measure of