Answer:
Approximate area of the circle: 254.34mm².
Approximate area of the triangle: 40.5mm².
Approximate area of the shaded region: 173.34mm².
Explanation:
From the diagram, it appears that two isosceles right triangles meet at the center of a circle with radius 9.
The area of a circle can be expressed as
, so the area of this circle is
mm².
The area of each of the isosceles right triangles is
mm².
The area of the shaded region is then the total area of the circle minus the total area of the triangles (since there are two, their total area is 81), which is then
mm².