Iknow the diameter of a circle is 10in. how do i find the area use pie

What is the exact area of a circle with a diameter of 50 centimeters? a.87.9 square centimeters b.379.9 square centimeters c.1962.5 square centimeters d.4923.5 square centimeters

In the diagram, gef and hef are congruent. what is the value of x

Solve the following pair of equations for x and y: ax/b_ by /a= a +b; ax - by = 2ab