<span>The area of the square is d^2. The area of the circle sandbox is πr^2=πd^2/4. So the area of play area only is equal to square area minus circle area which is d^2-πd^2/4.</span>
We can use Pythagorean's Theorem in order to find the remaining side length
a^2+b^2=c^2
Let a be the shadow length
Let b be the height of the flagpole
Let c be the hypotenuse
28^2+b^2=35^2
784+b^2=1225
b^2=1225-784
b^2=441
b=√441
b=21
Therefore the flagpole is 21 meters tall.
Hope this helps!
It would be a + because the 7 in 7y is positive, therefore it would be added to the X’s. if it was -7y, then the underline would be a –.