8. A regular pentagon ABCDE and a square ABFG are formed on opposite s

1.	8. A regular pentagon ABCDE and a square ABFG are formed on opposite sides of[NCERT Exemplar]AB. Find BCF
Answer» ABCDE is a regular pentagon and ABFG is a square. So the sides of pentagon and square are equal. Each angle of square = 90° Each angle of regular pentagon = 108° From the figure <FBC =360 - [<ABF + <ABC] <FBC = 360 - (90 +108 ) =360 - 198 = 162° <BFC = <BCF (since BF = BC, Δ BCF isosceles triangle ) <BCF= 1/2(180 - 162) =9°

8. A regular pentagon ABCDE and a square ABFG are formed on opposite sides of[NCERT Exemplar]AB. Find BCF

Answer»

ABCDE is a regular pentagon and ABFG is a square.

So the sides of pentagon and square are equal.

Each angle of square = 90°

Each angle of regular pentagon = 108°

From the figure <FBC =360 - [<ABF + <ABC]

<FBC = 360 - (90 +108 ) =360 - 198 = 162°

<BFC = <BCF (since BF = BC, Δ BCF isosceles triangle )

<BCF= 1/2(180 - 162) =9°