pi*radius squared = 81 square units
Divide both sides by pi and then square root both sides to find the value of the radius.
radius = 5.077706252 or 5 units in length to one significant figure
2 times radius = diameter = 10 units in length
The radius of the circle is the length between the middle of the circle and any of the sides. It is also half the lenght of the diameter.
The radius of a circle is half the diameter.
The radius is 1/2 of the diameter, so if the radius is 20 units then the diameter is 40 units. You multiply the radius by 2 to get the diameter.
Circumference = 2 x pi x radius = 24 pi 2 x radius = 24 ; radius = 12 units
A circle with a radius of 5 units has an area of 78.54 square units.
A circle with a radius of 2 units has an area of 12.57 square units.
1,438.72 square units.
8 units; the diameter of a circle is twice its radius.
diameter = 30 units area = 225*pi square units
The radius of the circle is 1.5 units and the diameter is 3 units.
Radius = 1/2 of the diameter = 30 units
The radius of the circle is the length between the middle of the circle and any of the sides. It is also half the lenght of the diameter.
The radius of a circle is half the diameter.
radius = diameter/2 area of a circle in square units = pi*radius2
Diameter = 50 units so the radius will be 25 units Area of a circle = pi*radius2 = pi*252 = 1963.495408 square units Or: 1963.5 square units correct to one decimal place.
diameter = 153.86 units so the radius is half of this and will = 76.93 units area of a circle = pi*radius2 area = pi*76.732 = 18496.10444 square units
The radius is 1/2 of the diameter, so if the radius is 20 units then the diameter is 40 units. You multiply the radius by 2 to get the diameter.