Area of the circle = π * (35 yd)^2
Let <em>A</em> be the area of the sector subtended by a central angle measuring 80º. Then
<em>A</em> / (π * (35 yd)^2) = 80º / 360º ==> <em>A</em> = 2450π/9 yd^2 ≈ 854.78 yd^2
Subtract from <em>A</em> the area of the triangle, whose base has length 45 yd and with height 25 yd:
<em>A</em> - 1/2 * (45 yd) * (25 yd) ≈ 292.28 yd^2
This is the area of the missing circular segment.
Then the area of the playground is equal to the area of the circle minus this area,
π * (35 yd)^2 - 292.28 yd^2 ≈ 3554 yd^2