Question

I really need help please!

Answer 1

As we know that angle of semi circle is 180°.

Here,

FLG = 40°

GLH = ?

HLJ = 60°

FLG + GLH + HLG = 180°

40° + GLH + 60° = 180°

GLH + 100° = 180°

GLH = 180° - 100°

GLH = 80°

Now,

FLH = 40° + 80° = 120°

$\sf \: Length \: of \: an \: arc \: of \: GHF = \dfrac{ \theta}{360} \times 2 \pi \: r$

$= \dfrac {120}{360} \times 2 \times \dfrac{22}{7} \times r$

$= \frac{1}{3} \times \frac{44}{7} \times r$

$= \frac{44}{21} \times r$

$= 2.09r$