Mathematics
If the area of a circle is 78.5 cm2, find its circumference. (Take π = 3.14)
Mensuration
8 Likes
Answer
By formula,
Area of circle = πr2
⇒ πr2 = 78.5
⇒ 3.14r2 = 78.5
⇒ r2 = = 25
⇒ r = = 5 cm.
Circumference = 2πr = 2 × 3.14 × 5 = 31.4 cm.
Hence, circumference = 31.4 cm.
Answered By
6 Likes
Related Questions
Calculate the area of the shaded region shown in figure (iii) given below. All measurements are in meters.
From a sheet of paper of dimensions 2 m × 1.5 m, how many circles of radius 5 cm can be cut? Also find the area of the paper wasted. (Take π = 3.14)
Asifa cut an aeroplane from a coloured chart paper (as shown in the adjoining figure). Find the total area of the chart paper used, correct to 1 decimal place.
From a square cardboard, a circle of biggest area was cut out. If the area of the circle is 154 cm2, calculate the original area of the cardboard.