Please answer all the questions correctly with proper statements.
1. The minute hand of a tower clock is 1.4 m long. How far does the tip of the hand move in 1 hour?
2. If the circumference of a circle exceeds its diameter by 30 cm, find the radius of the circle.
3. The circumference of a circle is 31.4 cm. Find the radius and the area of the circle.
4. How many times will the wheel of a car rotate in a journey of 88 km, given that the diameter of the wheel is 56 cm?
5. From square cardboard of a side of 21 cm, a circle of the maximum area is cut out. Find the area of the cardboard left.
6. A piece of wire is bent in the shape of an equilateral triangle of side 4.4 cm. If this wire is bent to form a circle, find the radius and the area of the circle.
7. A wire is in the form of a rectangle 18.7 cm long and 14.3 cm wide. If this wire is reshaped and bent in the form of a circle, find the radius and the area of the circle so formed.
The best answer to be marked as brainliest.
Answers
Answer:
1:-
2:- 15 cm
3:- 5 cm
4:- 50000
5:- Diameter of circle =Side of square
Diameter of circle = 21 cm
Radius of circle = 21 /2 cm
Area of circle = pi *r^2
= 22 * 21 * 21 /7 * 2* 2
= 22 * 21 * 3 / 4
= 462 * 3 /4
= 1386/4
= 346.5 cm^2
Area of cardboard left = Area of square - Area of circle
Area of cardboard left = 21*21 - 346.5
= 441 - 346.5
= 94.5 cm^2
6:-Length of wire = perimeter of △
=3×4.4⇒13.2cm
Now, the circumference of circle = length of wire
2πr=13.2
r=
2×π
13.2
r=2.1cm
Area of circle ⇒πr
2
⇒π×(2.1)
2
⇒13.86cm
2
7:-Perimeter of rectangle=(18.7+14.3)×2=33×2=66 cm
Circumference of circle= perimeter of rectangle
⇒2πr=66
⇒r=
2π
66
⇒r=
2
66
×
22
7
⇒r=
2
21
∴r=10.5 cm
So, radius of circle =10.5 cm
HOPE IT HELPS YOU
PLZ MARK ME AS BRAINLIEST
Answer:
............................