Question

Choose the option that best corrects the underlined word:
The radius of the two circles are of equal measure.

a) No change
 b)arc
 c)diameter
 d)radii

Answer 1

Hint: A noun that denotes one person or thing is said to be in the singular number., and a noun that denotes more than one person or thing is said to be in the plural number.

Complete step-by-step answer:

In the given question, we have to find out which of the given options replaces ‘radius’ to make the given sentence grammatically correct.
In the sentence, the noun is plural (‘two circles’). However, the word ‘radius’ is singular, which is inconsistent as the verb ‘are’ also denotes the existence of a plural noun. Therefore, ‘radius’ should be replaced by a plural noun.
Let us analyze the options given to us in this question:
Option (a.), 'no change', suggests that the word ‘radius’ in the sentence should remain as it is, and that the sentence is thus correct.
Therefore, option (a.) is incorrect as ‘radius’ should be replaced by a plural noun.

Option (b.), ‘arc', refers to a noun that is singular.
Therefore, option (b.) is incorrect as ‘radius’ should be replaced by a plural noun.

Option (c.), ‘diameter', refers to a noun that is singular.
Therefore, option (c.) is incorrect as ‘radius’ should be replaced by a plural noun.

Option (d.), ‘radii', refers to a noun that is plural.
Therefore, option (d.) is correct as ‘radius’ should be replaced by a plural noun.

Note: In this question, there should be consistency in terms of numbers in the given sentence. That is why we have to find the option which has a plural noun.