Find the area of the triangle

The circumference of a circle is 5 pi cm. what is the area of the circle?

How many 3-digit numbers can you write using only digits 1 and 7? (of course, digits can repeat.) how many 3-digit numbers can you write using only digits 1 and 7? (of course, digits can repeat.)

What is the slope of the line passing through the points (3, 3) and (5, 7) ? 1. 2 2. 1/2 3. −2 4. −1/2