4. As shown in Figure 5.111 to the right if the two small semicircles, each of radius 1 unit
with centres O' and O'' are contained in the
bigger semi-circle with center O, So that
O', O and O" are on the same line, then
what is the area of the shaded part?

Area of the shaded part is 3.14 square unit.

Step-by-step explanation:

Area of the shaded part = Area of large semicircle - (Area of two small semi circles)

Area of large semicircle with center O =

                                                                =

                                                                = 2π

Area of semicircle with center O' =

                                                      =

Area of semicircle with center O" =

Now substitute these values in the formula,

Area of shaded part =

                                  =

                                  = 3.14 square unit

Area of the shaded part is 3.14 square unit.

2 over 5

step-by-step explanation:

the 2: 3 ratio is the length of the ac segment to the cb segment total length. this implies that the ratio between segment ac length and segment ab length is 2: 5. point c is 2/5 from a to b, so the required fraction is 2/5.