Help him find the area of remaining portion of the square by giving answers
to his questions looking at the figure
(i) Find the area (in cm2
) of square ABCD.
(a) 64 (b) 81
(c) 49 (d) 100
(ii) Find the area (in cm2
) of each quadrant with radius 2 cm.
(a) 5.21 (b) 3.14
(c)5.26 (d) 4.36
(iii) Find the area (in cm2
) of circle with diameter 4 cm.
(a) 5 (b) 3
(c) 4 (d) 6
(iv) Write the formula for area of semi-circle with diameter d.
(a)
2
8
(b)
2
4
(c )
2
2
(d)
2
(v) Find the area (in cm2
) of the remaining portion of the square.
(a) 60 - 5π (b) 64 - 8 π
(c) 50 - 3π (d) 91 - 6 π
Answers
Answer:
third planet from the Sun and the only astronomical object known to harbor life. About 29% of Earth's surface is land consisting of continents and islands. The remaining 71% is covered with water, mostly by oceans but also lakes, rivers and other fresh water, which together constitute the hydrosphere. Much of Earth's polar regions are covered in ice. Earth's outer layer is divided into several rigid tectonic plates that migrate across the surface over many millions of years. Earth's interior remains active with a solid iron inner core, a liquid outer core that generates Earth's magnetic field, and a convecting mantle that drives plate tectonics.
Earth
Astronomical symbol of Earth
The Blue Marble photograph of Earth, taken by the Apollo 17 mission. The Arabian peninsula, Africa and Madagascar lie in the upper half of the disc, whereas Antarctica is at the bottom.
The Blue Marble, the most widely used photograph of Earth,[1][2] taken by the Apollo 17 mission in 1972.
Designations
Alternative names
Gaia, Gaea, Terra, Tellus, the World, the Globe
Adjectives
Earthly, terrestrial, terran, tellurian
Orbital characteristics
Epoch J2000[n 1]
Aphelion
152100000 km (94500000 mi)[n 2]
Perihelion
147095000 km (91401000 mi)[n 2]
Semi-major axis
149598023 km (92955902 mi)[3]
Eccentricity
0.0167086[3]
Orbital period
365.256363004 d[4]
(31558.1497635 ks)
Average orbital speed
29.78 km/s[5]
(107200 km/h; 66600 mph)
Mean anomaly
358.617°
Inclination
7.155° to the Sun's equator;
1.57869°[6] to invariable plane;
0.00005° to J2000 ecliptic
Longitude of ascending node
−11.26064°[5] to J2000 ecliptic
Time of perihelion
2021-Jan-02 13:59[7]
Argument of perihelion
114.20783°[5]
Satellites
1 natural satellite: the Moon
5 quasi-satellites
>1 800 operational artificial satellites[8]
>16 000 space debris[n 3]
Physical characteristics
Mean radius
6371.0 km (3958.8 mi)[9]
Equatorial radius
6378.1 km (3963.2 mi)[10][11]
Polar radius
6356.8 km (3949.9 mi)[12]
Flattening
0.0033528[13]
1/298.257222101 (ETRS89)
Circumference
40075.017 km equatorial (24901.461 mi)[11]
40007.86 km meridional (24859.73 mi)[14][n 4]
Surface area
510072000 km2 (196940000 sq mi)[15][n 5]
148940000 km2 land (57510000 sq mi)
361132000 km2 water (139434000 sq mi)
Volume
1.08321×1012 km3 (2.59876×1011 cu mi)[5]
Mass
5.97237×1024 kg (1.31668×1025 lb)[16]
(3.0×10−6 M☉)
Mean density
5.514 g/cm3 (0.1992 lb/cu in)[5]
Surface gravity
9.80665 m/s2 (1 g; 32.1740 ft/s2)[17]
Moment of inertia factor
0.3307[18]
Escape velocity
11.186 km/s[5]
(40270 km/h; 25020 mph)
Sidereal rotation period
0.99726968 d[19]
(23h 56m 4.100s)
Equatorial rotation velocity
0.4651 km/s[20]
(1674.4 km/h; 1040.4 mph)
Axial tilt
23.4392811°[4]
Albedo
0.367 geometric[5]
0.306 Bond[5]
Surface temp. min mean max
Kelvin 184 K[21] 287.16 K[22] (1961–90) 330 K[23]
Celsius −89.2 °C 14.0 °C (1961–90) 56.7 °C
Fahrenheit −128.5 °F 57.2 °F (1961–90) 134.0 °F
Atmosphere
Surface pressure
101.325 kPa (at MSL)
Composition by volume
78.08% nitrogen (N
2; dry air)[5]
20.95% oxygen (O
2)
~ 1% water vapor (climate variable)
0.9340% argon
0.0413% carbon dioxide[24]
0.00182% neon[5]
0.00052% helium
0.00019% methane
0.00011% krypton
0.00006% hydrogen
According to radiometric dating estimation and other evidence, Earth formed over 4.5 billion years ago. Within the first billion years of Earth's history, life appeared in the oceans and began to affect Earth's atmosphere and surface, leading to the proliferation of anaerobic and, later, aerobic organisms. Some geological evidence indicates that life may have arisen as early as 4.1 billion years ago. Since then, the combination of Earth's distance from the Sun, physical properties and geological history have allowed life to evolve and thrive. In the history of life on Earth, biodiversity has gone through long periods of expansion, occasionally punctuated by mass extinctions. Over 99% of all species that ever lived on Earth are extinct. Almost 8 billion humans live on Earth and depend on its biosphere and natural resources for their survival. Humans increasingly impact Earth's hydrology, atmospheric processes and other life.
Earth's atmosphere consists mostly of nitrogen and oxygen. Tropical regions receive more energy from the Sun than polar regions, which is redistributed by atmospheric and ocean circulation. Greenhouse gases also play an important role in regulating the surface temperature. A region's climate is not only determined by latitude, but also by its proximity to moderating oceans and height among other factors. Extreme weather, such as tropical cyclones and heat waves, occurs in most areas and has a large impact on life.