In a circle of radius 21 cm, an arc subtends an angle of 60° at the centre. Find: (i) The length of the arc (ii) Area of the sector formed by the arc (iii) Area of the segment forced by the corresponding chord

It is given that, Radius of a circle = $$21$$ cm. We know that $$\pi = 22/7$$, So the circumference of a circle = $$2 \pi r$$ Substituting the values, $$= 2 * 22/7 * 21$$ So we get, $$= 2 * 22 * 3$$ $$= 132$$ cm.

Let it be filled to height 'h'cm. Then the part not in water is (21-h)cm. So the apparent depth of the filled portion must be (21-h)cm. r e a l d e p t h a p p a r e n t d e p t h = r e f r a c t i v e i n d e x o f w a t e r h 21 − h = 1.33 h = 12 c m hence, 12cm water should be filled in a container.

In a circle of radius 21 cm, an arc subtends an angle of 60° at the centre. Find: (i) The length of the arc (ii) Area of the sector formed by the arc (iii) Area of the segment forced by the corresponding chord

Question 20 Find the difference of the areas of a sector of angle 120 ∘ and its corresponding major sector of a circle of radius 21 cm.

In a circle of radius 21 cm, an arc subtends an angle of 60° at the centre. Find: (i) The length of the arc (ii) Area of the sector formed by the arc (iii) Area of the segment forced by the corresponding chord

The volumes of two spheres are in the ratio 27:64. Find their radii if the sum of their radii is 28 cm.

In the given figure, two concentric circles with center O have radii 21 cm and 42 cm. If ∠ A O B = 60 0 , then find the area of the shaded region. View Solution

The radius of a circle is 21 cm. Find the perimeter and area of a quadrant of the circle. View Solution. Q4.

Most of the hydrogen gas in the interstellar medium is in cold atomic form or molecular form. Hendrik van de Hulst predicted that the cold atomic hydrogen (H) gas should emit a particular wavelength of radio energy from a slight energy change in the hydrogen atoms. The wavelength is 21.1 cm (frequency = 1420.4 MHz).