2. The radil of two circles are 8 cm and 6 cm
respectively. Find the radius of the circle having area
Answers
Correct Question:-
The radii of two circles are 8 cm and 6cm respectively . find the radius of the circle having area equal to the sum of the areas of the two circle
We have 2 circles, whose radii are 8cm and 6cm respectively.
We then have a bigger circle whose area is the sum of the areas of these smaller circles. So we have to find the areas of these circles and then add them.
The area of a circle = π ×r×r
So the area of the first circle is
π × 8cm × 8cm = 201.088 squared cm
The area of the second circle is
π × 6cm × 6cm = 113.112 squared cm
When we add the areas of these two circles;
208.088 + 113.112 = 314.2 squared cm
314.2 squared cm is the area of the big circle, yet we need its radius.
314.2 = π × r × r
π = 3.142
So we evaluate
314.2 = 3.142 × squared r
Dividing both sides by 3.142, we get
100 = squared r
We then get the square roots of both sides
√100 = √ squared r
The square root of 100 is 10cm.
Hence r = 10cm.
Correct Question:-
The radii of two circles are 8 cm and 6cm respectively . find the radius of the circle having area equal to the sum of the areas of the two circle
We have 2 circles, whose radii are 8cm and 6cm respectively.
We then have a bigger circle whose area is the sum of the areas of these smaller circles. So we have to find the areas of these circles and then add them.
The area of a circle = π ×r×r
So the area of the first circle is
π × 8cm × 8cm = 201.088 squared cm
The area of the second circle is
π × 6cm × 6cm = 113.112 squared cm
When we add the areas of these two circles;
208.088 + 113.112 = 314.2 squared cm
314.2 squared cm is the area of the big circle, yet we need its radius.
314.2 = π × r × r
π = 3.142
So we evaluate
314.2 = 3.142 × squared r
Dividing both sides by 3.142, we get
100 = squared r
We then get the square roots of both sides
√100 = √ squared r
The square root of 100 is 10cm.
Hence r = 10cm.