In figure find the area of the red part.

Step-by-step explanation:

Given : A rectangle 4 x 8 , a semicircle

Diagonal intersecting semicircle  

To Find :Area of red part

Angle AC make AB   α = ∠BAC

tan α = BC/AB = 4/8 = 1/2

=> α = 26.565°

∠ECA = ∠BAC = α

EC = EF = 4

=> ∠CEF = 180° - 2α

∠AED = 45°  as   AE is  diagonal of Square of side  4

=> ∠AEF  + 180° - 2α + 45° = 180°

=>  ∠AEF =  2α - 45°  = 8.13°

in Left side area  between square  and circle is split in 2 Equal parts

(1/2) area - area AFG = area of Red part

in Left side area  between square  and circle  = 4² - (1/4)π4²

= 3.4336 sq unit

half  =  1.7168 sq unit  

Now find area AFG = area ΔAEF - sector EGF

area ΔAEF  

AE = 4√2  , EF = 4    angle = 8.13°

area ΔAEF   = (1/2) 4√2 * 4 sin 8.13° = 1.6 sq unit

area  sector EGF  = (8.13/360)π4² = 1.135  sq unit

area AFG  = 1.6 - 1.135  = 0.465 sq unit

Area of Red part = 1.7168 - 0.465 sq unit

= 1.2518 sq unit

= 1.252  sq unit

= 1.25 sq unit.

Hope this helps!!

sin3a=12/15

step-by-step explanation:

since one side was multiplied by 3 the other side must also be multiplied by 3.

b: |12 – x| ≤ 0.25

step-by-step explanation:      

let x be the possible lengths in inches, of the ribbons jaime cut.

we have been given that jaime is cutting strips of ribbon for a project. he tries to cut each piece to be 12 inches long, but sometimes he cuts it too long or too short by as much as 0.25 inch.  

we can represent this information in an inequality as:

by the definition of absolute value function we will get,

upon combining our inequalities we will get,

therefore, the inequality   describes all the possible lengths (x), in inches, of the ribbons jaime cut.

step-by-step explanation: