2 A and B please with explanation! BIG POINTS please explain

see explanation

Step-by-step explanation:

Using the ratio equality for circles

=

(a)

Note the angle at the centre of the shaded arc is 360° - 90° = 270°, thus

= = ( cross- multiply )

3C = 180 ( divide both sides by 3 )

C = 60 mm

(b)

Note the angle at the centre of the shaded arc is 360° - 135° = 225°, thus

= ( cross- multiply )

225C = 1188 ( divide both sides by 225 )

C = 5.28 cm

the answer is d

step-by-step explanation:

6.9

step-by-step explanation:

simple math really

6 1/2 times 0.6 = 3.9

but if you are just doing 6 and not 6 1/2 then the answer is 3.6