Show that the angles of an equilateral triangle are 60°

Use set buikder notation to represent the following set: {, -2, -1, 0}

Aubrey read 29 books and eli read 52 books what number is equal to the number of books aubrey read?

Suppose that sahil knows that 45 people with ages of 18 to 29 voted. without using a calculator, he quickly says then 135 people with ages of 30to 49 voted. is he correct? how might sohil have come up with his answer so quickly?