please solve this plz plz,plz plz,plz plz,plz plz,plz do only tick ones that are 14, 15, 18, 20, 22, 25
Answers
14. given that diameter of circle is 56 m
we know that diameter of a circle = 2r = 56
⇒ r = 28
circumference of the circle = 2πr = 2 × 3.14 × 28 = 176 m
cost of one meter = 80 rupees
⇒ cost of 176 meter = 80 × 176 = 14074 rupees.
15.given radius of 1st circle = 20 cm
circumference of the 1st circle = 2 × π × 20 = 125.6 cm
given radius of 2nd circle = 13 cm
circumference of the 2nd circle = 2 × π × 13 = 81.6 cm
difference between circumference of these two circles = 44 cm
18. given radius of 1st circle = 15cm
circumference of the 1st circle = 2 × π × 15= 94.24 cm
given radius of 2nd circle = 8cm
circumference of the 2nd circle = 2 × π × 8 = 50.24 cm
the circumference of larger circle = sum of circumferences of 1st and 2nd circle = 94.24 + 50.24 = 144.4cm
⇒ 2πr = 144.4
⇒ r = 23 cm
20. the circumference of circle with 12cm diameter = 2×π ×12 = 75.4cm
the circumference of the larger circle is 8 times the 12cm radius circle
⇒ circumference of the larger circle = 8 ×75.4 = 603.18
⇒ 2×π × r = 603.18
⇒diameter of larger circle = 603.18/π = 192 cm
22.the circumferences of two circles are in the ratio 5:7
⇒ 2×π × r₁ : 2×π × r₂ = 5 : 7
⇒ r₁ : r₂ = 5:7
25. perimeter of sqaure = 4 × side of square
given side of square = 44
⇒ perimeter of square = 4 × 44 = 176cm
this perimeter of square = circumference of circle
⇒ 2πr = 176
radius of circle = 176/2π = 28cm