1. In a circle, the height of an arc is 21 cm and the diameter is 84 cm. Find the chord of ‘half of the arc’
Write Comment
Comments
By: anil on 05 May 2019 02.40 am
Let ABC be the arc as shown in the figure. It is known that the diameter of the circle = 84 cm. Hence, the radius of the circle = 42 cm. We can see that both CO and BO are equivalent to the radius of the circle. Hence, CO = 42 cm and BD = BO - OD = 42 - 21 = 21 cm. In triangle ODC, $$cosDOC = dfrac{21}{42}$$ Hence, $$angle$$ DOC = 60° In triangle BOC, OB = OC. Hence, we can say that $$angle$$ OCB = $$angle$$ OBC = 60°. Therefore, OBC is an equilateral triangle. Hence, OB = OC = BC = 42 cm. Hence, we can say that the length of the chord of ‘half of the arc’ = 42 cm. Therefore, option C is the correct answer.
Terms And Service:We do not guarantee the accuracy of available data ..We Provide Information On Public Data.. Please consult an expert before using this data for commercial or personal use