Question

20.If a cone of radius 4cm and height 3cm is melted and recast into a
cylinder of height 4cm then find radius of a cylinder is​

Answer 1

Given :-

• If a cone of radius 4cm and height 3cm is melted and recast into a cylinder of height 4cm

To find :-

• Radius of cylinder

Solution :-

• Radius of cone (r) = 4 cm
• Height of cone (h) = 3 cm

It is given that cone recast into a cylinder then

• Height of cylinder (h) = 4 cm

As we know that

→ Volume of cone = volume of cylinder

→ ⅓ πr²h = πr²h

Cancel π

→ ⅓ × r² × h = r² × h

Putting the values of height and radius

→ ⅓ × (4)² × 3 = r² × 4

→ 16 = r² × 4

→ r² = 16/4

→ r² = 4

→ r = √4

→ r = ± 2

• Radius never in negative

Therefore,

• Radius of cylinder is 2 cm

More to know :-

• Area of circle = πr²
• Circumference of circle = 2πr
• Perimeter of rectangle =2(l + b)
• Perimeter of square = 4 × side
• Area of square = side × side
• Area of rhombus = ½ × product of diagonals
• Area of Parallelogram = base × height
• Area of trapezium = ½ × sum of parallel sides × height

Answer 2

Answer:

i hope it helps................................

Step-by-step explanation: