When the minute hand moves 45 minutes, it covers three-fourths of the clock face. This is called a three-quarter turn. A three-quarter turn is more than a straight angle but less than a full turn.
Class 5 NCERT Maths-Mela Chapter 3 Angles as Turns solution
class 5 Maths-Mela Mathematics Textbook Chapter 3 Angles as Turns question answer
A right angle is formed by a quarter turn. Since a full turn is equal to four quarter turns, we can say that a full turn contains exactly four right angles. For example, when the minute hand of a clock moves from 12 to 3, 3 to 6, 6 to 9 and finally 9 to 12, it has completed four right angles. Together, these four right angles form one complete turn.
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