▢MRPN is cyclic, ∠ R = (5x – 13)°, ∠ N = (4x + 4)°. Find measures of ∠ R and ∠ N.
Chapter 3 – Circle – Text Book Solution
Practice Set 3.4 | Q 3 | Page 73
▢MRPN is cyclic, ∠ R = (5x – 13)°, ∠ N = (4x + 4)°. Find measures of ∠ R and ∠ N.
MRPN is a cyclic quadrilateral.
∴ ∠R + ∠N = 180º (Opposite angles of a cyclic quadrilateral are supplementary)
⇒ 5x − 13º + 4x + 4º = 180º
⇒ 9x − 9º = 180º
⇒ 9x = 180º + 9º = 189º
⇒ x = 21º
∴ ∠R = 5x − 13º = 5 × 21º − 13º = 105º − 13º = 92º
∠N = 4x + 4º = 4 × 21º + 4º = 84º + 4º = 88º
Thus, the measures of ∠R and ∠N are 92º and 88º, respectively.
Explanation:-
Using the fact that opposite angles of a cyclic quadrilateral are supplementary, we have:
∠R + ∠N = 180°
Substituting the given values, we get:
5x – 13° + 4x + 4° = 180°
Combining like terms and simplifying, we get:
9x – 9° = 180°
Adding 9° to both sides, we get:
9x = 189°
Dividing by 9, we get:
x = 21°
Substituting this value for x, we can find the measures of angles R and N:
∠R = 5x – 13° = 5(21°) – 13° = 105° – 13° = 92°
∠N = 4x + 4° = 4(21°) + 4° = 84° + 4° = 88°
Therefore, the measures of angles R and N are 92° and 88°, respectively.
Chapter 3 – Circle – Text Book Solution
Practice set 3.4 | Q 3 | Page 73
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