Polygons - Mathematics Jamb Past Questions and Answers

Question 11 :

• JAMB 1980

In triangle FGB, < G = 90^o, < H = 60^o, while in triangle XYZ, < X = 60^o and < Y = 30^o. Form XYZ write down the ratio equal to \(\frac{FG}{FH}\)

A. \(\frac{YX}{ZX}\)
B. \(\frac{YX}{YZ}\)
C. \(\frac{ZX}{YZ}\)
D. \(\frac{YZ}{XY}\)

Question 12 :

• JAMB 1980

A pentagon has four of its angles equal. If the size of the fifth angle is 60^o, Find the size of each of the four equal angles.

A. 60^o
B. 108^o
C. 120^o
D. 150^o
E. None of the above

Question 13 :

• JAMB 1980

Simplify the given expression \(\sqrt{\frac{1 - cos x}{1 + cos x}}\)

A. \(\frac{1 - cos x}{sin x}\)
B. 1 - cos x
C. Sin x
D. 1 + cos x
E. \(\frac{1 + cos x}{sin x}\)

Question 14 :

• JAMB 1981

What is the size of an exterior angle of a regular pentagon?

A. 36^o
B. 60^o
C. 72^o
D. 120^o
E. 360^o

Question 15 :

• JAMB 1982

In a regular polygon of n sides, each interior angle is 144o. Find n

A. 12
B. 11
C. 10
D. 8
E. 6F