# en

 Task Calculate the surface area of the gray circular segment using the radius r = 4.0 cm and the arc length b = 5.0 cm!

(Round to 1 decimal place!)

Tip:

Calculate angle α first

The dotted height of the triangle and half of the length s can be calculated as you now know all of the angles in the small rectangular triangles

Then calculate the surface area of the big triangle and via this and the surface area of the circular sector the area of the marked figure.

bitte warten

 Note Click inside the bright gray box. It turns turquoise. Enter your solution. You may also use the menu, which is available via rightclick. Complete your input with the RETURN-key. Green: right. Orange: wrong See also: Using the Formel-Applet
 Solution $A=$   2,4cm²    (Select the red area to see the solution) $alpha=$   71,6°    (Select the red area to see the solution)