Class 10th cbse please answer them I am practicing for broad exam

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

The graph shows the distance y, in inches, a pendulum moves to the right (positive displacement) and to the left (negative displacement), for a given number of seconds x. how many seconds are required for the pendulum to move from its resting position and return? enter your answer in the box.

Triangle xyz has vertices x(1,3), y(0,0)