Question

the shape and size of bright side of moon appears to change gradually everyday give reason

Answer 1

although one half of the moon is always illuminated by the sun's light, the "lighted up' portion, of the Moon appears to change shape as viewed from earth. "This is due to the changes in the relative position of the earth and the sun and the moon."

Answer 2

It takes nearly 29.5 solar days for the moon to make one finish Revolution around the earth. although one half of the moon is always illuminated by the sun's light, the "illuminated' portion, of the Moon appears to change shape as saw from earth.

"This is because of the changes in the relative position of the earth and the sun and the moon." during the first half the of moon's Orbit the Moon's apparent size grows (waxes). during the remaining half of its Orbit, the shape of moon appears to decrease (wanes) in size.