Question

Petra is making a batch of extra large donuts by stamping circles in dough using a pastry

stamp with a diameter of 5 inches. For the donut hole, she stamps out a circle using a pas-
try stamp that has a diameter of 2 inches.
How many square inches of dough are left in the donut after the hole has been removed?
Step 1 - Find the radius of each circle
Step 2 - Find the area of the large circle
Step 3 - Find the area of the small circle
Step 4 - Area of large circle minus area of small circle
Area = πtr²

Answer 1

To find the area of dough left in the donut after the hole has been removed, we can follow these steps:

Find the radius of the large circle: Since the pastry stamp has a diameter of 5 inches, the radius of the large circle is 5/2 = 2.5 inches.

Find the area of the large circle: The area of a circle is given by the formula A = πr², where r is the radius. So, the area of the large circle is A = π(2.5)² = 19.63 square inches.

Find the radius of the small circle: Since the pastry stamp for the donut hole has a diameter of 2 inches, the radius of the small circle is 2/2 = 1 inch.

Find the area of the small circle: Using the same formula as before, the area of the small circle is A = π(1)² = 3.14 square inches.

Find the area of dough left in the donut: To find the area of dough left in the donut, we need to subtract the area of the small circle from the area of the large circle. So, the area of dough left in the donut is 19.63 - 3.14 = 16.49 square inches.

Therefore, there are 16.49 square inches of dough left in the donut after the hole has been removed.