john painted the face of a circular clock of radius 21cm, which is divided into four parts, using four different colours, find the area of each equal coloured part. [use π = 22/7]​

Respuesta :

Answer: 346.5 square cm (approximate)

Work Shown

A = area of a circle

A = pi*r^2

A = (22/7)*r^2 ... which is approximate

A = (22/7)*(21)^2

A = 1386

The full circle has approximate area 1386 square cm.

Divide this by 4 to get the area of each quarter portion.

1386/4 = 346.5

Answer:

346.5 cm²

Step-by-step explanation:

Given that the circular clock is divided into four equal parts, we can find the area of each part by finding a quarter of the area of a circle with a radius of 21 cm.

The formula for the area of circle with radius r is A = πr². Therefore, the formula for the area of a quarter of a circle is:

[tex]\textsf{Area of a quarter of a circle}=\dfrac{\pi r^2}{4}[/tex]

Substitute r = 21 and π = 22/7 into the equation:

[tex]A=\dfrac{\frac{22}{7} \cdot 21^2}{4}[/tex]

Solve:

[tex]A=\dfrac{\frac{22}{7} \cdot 441}{4}[/tex]

[tex]A=\dfrac{\frac{9702}{7}}{4}[/tex]

[tex]A=\dfrac{1386}{4}[/tex]

[tex]A=346.5\; \sf cm^2[/tex]

Therefore, the area of each coloured part of the circular clock is:

[tex]\huge\boxed{\boxed{346.5\; \sf cm^2}}[/tex]