As shown in the figure: the area of an isosceles right triangle in a circle is 5 square centimeters. How to calculate the area of a circle? How to write the calculation process

As shown in the figure: the area of an isosceles right triangle in a circle is 5 square centimeters. How to calculate the area of a circle? How to write the calculation process

Let the length of the right side of the isosceles right triangle be a, then: (1 / 2) a ^ 2 = 5, a ^ 2 = 10, the hypotenuse of the triangle is the diameter of the circle D, and d ^ 2 = 2 (a ^ 2) = 20s circle = 3.14r ^ 2 = 3.14 (D / 2) ^ 2 = 3.14 * (d ^ 2) / 4 = 3.14 * 5 = 15.7 (square centimeter) x ^ 2 means square, for example 5 ^ 2 = 25, sorry, I can't square those footmarks