NCERT Exemplar Solutions
Class 7 - Mathematics - Unit 5: Lines And Angles - Problems and SolutionsQuestion 81
Class 7 - Mathematics - Unit 5: Lines And Angles - Problems and Solutions
Question. 81
81. If two angles have a common vertex and their arms form opposite rays (Fig. 5.41), then:
(a) How many angles are formed?
(b) How many types of angles are formed?
(c) Write all the pairs of vertically opposite angles.
Answer:
(a) 13
(b) Linear pair, Supplementary, Vertically opposite, Adjacent
(c) ∠1 and ∠3; ∠2 and ∠4
Detailed Answer with Explanation:
Four rays from a common point form 13 angles. These include various types. Vertically opposite pairs are (1,3) and (2,4).