Question

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

Answer 1

Answer:

see explanation

Step-by-step explanation:

Using the ratio equality for circles

$\frac{arc}{C}$ = $\frac{angleatcentre}{360}$

(a)

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

$\frac{45}{C}$ = $\frac{270}{360}$ = $\frac{3}{4}$ ( 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

$\frac{3.3}{C}$ = $\frac{225}{360}$ ( cross- multiply )

225C = 1188 ( divide both sides by 225 )

C = 5.28 cm