10. P(lat 400N, long 18°W) and Q(lat 400N, long 78OW) are two cities on the surface of the earth. Calculate, the: (a) the radius of the parallel of latitude on which P and Q lie, correct to the nearest 10km;
(b) length of the minor arc PQ, correct to the nearest 100 km;
(c) the vertical distance between the centre of the earth and the centre of the small circle on which P and Q lie, correct to the nearest km.
[Take π = 22/7 and radius of the earth= 6400 km]​

answer: 25.4 units

step-by-step explanation: radius = 12.7 units

diameter = twice the radius

diameter = 12.7 x 2

= 25.4

the answer is d. 75%

answer: (-8,4) are the coordinates of a

step-by-step explanation:

let the side of square abcd is x .

thus the area of square abcd is .

now, by the diagram area of triangle ead= 1/2 × ea × ad = 1/2 × ea × x

( because ad is the side of square)

and, according to the question,

the areas of square abcd and right ead are equal.

⇒

⇒ea=2x

thus, ea: ab=2: 1

therefore, point a divides line segment eb into the ratio 2: 1.

⇒ by sectional formula coordinates of a are,

=

=

=(-8, 4)

thus the coordinates of a are (-8,4)