Question

The diameter of circle increase by 10 cm .Find the increase% in its area.​

Answer 1

Step-by-step explanation:

Whatever we increase the diameter by, we also increase the radius by the same length. By this logic, we know that if the diameter is increased by 10%, then so is the length of the radius. Since we don’t know the length of the radius of the original circle, we can assign it to the variable r . This means that the length of the new radius is equivalent to 1.1r.

Then, we can substitute the value of the new radius in the equation πr2 to find the percentage increase in the area. Solving for this expression, we get 1.21π . This tells us that the total area of the circle increases by 21% when the diameter is increased by 10%.

21%