Three angles of a nonagon are equal and the sum of six other angles is...

JAMB 1987

Three angles of a nonagon are equal and the sum of six other angles is 1110^o. Calculate the size of one of the equal angles.

A. 210^o
B. 150^o
C. 105^o
D. 50^o

WAEC and NECO CBT Software for Computers and Laptops - Candidates, Schools, Centres, Resellers - 100% Offline -Download Now

Your School's Whatsapp Group - Join Us now

Post-UTME Past Questions - Original materials are available here - Download PDF for your school of choice + 1 year SMS alerts

Correct Answer: Option D

Explanation

Sum of interior angles of any polygon is (2n - 4) right angle; n angles of the nonagon = 9

where 3 are equal and 6 other angles = 1110^o

( 2 x 9 - 4)90^o = (18 - 4)90^o

= 14 x 90^o = 1260^o

9 angles = 12600, 6 angles = 1110^o

Remaining 3 angles = 1260^o - 1110^o = 150^o

size of one of the3 angles \(\frac{150}{3}\) = 50^o

Previous Next

Go back to Maths classroom

Report an Error Ask A Question Download App