area of a circle = area of a rectangle(parallelogram) formed by the sectors of circle with pi as length and radius as bradth.
It depends on the relationship between the rectangle and the circles.
The relationship between the area of a triangle and a rectangle is a Triangle is base times height divided by 2. Area of a rectangle is length times height.
The area of the circle is 50.265482457436691815402294132472 inches2. The area of the rectangle is 210 inches2. The rectangle is larger in area by 159.73451754256330818459770586753 inches2,
It is not possible to provide any kind of answer without information on the relationship - if any - between the triangle and the rectangle.
There is no simple relationship between area and perimeter. For the same area, you can have different perimeters, depending on whether the enclosed area is a square, a 2:1 rectangle, a 3:1 rectangle, etc., a circle, a 2:1 ellipse, a regular pentagon, etc.
The relationship between the radius and area of a circle is as follows: Area of circle = 3.14 x Radius x Radius or 22/7 x Radius x Radius
The answer will depend on the relationship - if any - between the rectangle and the triangle.
In relation to the area of a circle: pi*radius^2
The largest rectangle inscribed in a circle would be the inscribed square. You can calculate the area of the square by the fact that its diagonal is the diameter of the circle.
Calculate the area of a rectangle and of the semicircle separately, then add.