Question

Pls help!! Find the area of the lighter shaded region and round to the nearest tenth.

Answer 1

Answer: =approx 5.13 cm²

Explanation:

Lets find the area of the region that is blue ( dark blue+light blue)

S= pi*r^2/360*80=pi*25*2/9=pi*50/9

The lighter region' s area is the S- S(triangle marked with dark blue)

The area of this triangle is r^2*sin(80°)/2= 25*sin(80°)/2=

=12.5*sin(80°)

So the required area Sreg= pi*50/9-12.5*sin(80°)=

= approx 3.14*50/9-12.5*0.985=approx 5.13 cm²

Answer 2

5.1 cm² approximately

Explanation:

A lighter= Area inscribed -1/2r² sin80°

A lighter=π r² (80°/360°) -1/2(5 cm)² sin 80°

A lighter=π(5cm)² (80°/360°) -1/2(5 cm)² sin 80°

A lighter=3.14*25cm²(80°/360°) - 12.5cm² sin 80°

A lighter=17.444…cm² - 12.31009... cm²

A lighter=5.13cm² approximately