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

The correct option is D radii

Option A: In the given sentence, the noun 'two circles' is plural. So, there should be a consistency in terms of number in a sentence. The word 'radius' is singular, it refers to only one radius, whereas 'circles' is plural. Hence this word must be changed and option A is incorrect.

Option D: 'Radii' is the plural form of 'radius' and hence agrees with the rest of the sentence in terms of number. Hence option D is correct.

Options B and C: 'Arc' and 'diameter' are both singular nouns and, like 'radius', do not agree with the sentence in number. Hence these options are incorrect.