7. NOT TO
SCALE
8.
Р
С
B
In the diagram. PQ is parallel to BC.
APB and AQC are straight lines.
PQ = 8 cm, BC = 10 cm and AB = 9 cm.
Calculate PB

PB = 1.8

Step-by-step explanation:

PQ = 8 cm, BC = 10 cm and AB = 9 cm

∆ABC is similar to ∆APQ.

Therefore:

Plug in the values

Cross multiply

AP × 10 = 8 × 9

AP × 10 = 72

Divide both sides by 10

AP = 7.2

PB = AB - AP

PB = 9 - 7.2

PB = 1.8

3. r√2

Step-by-step explanation:

The chord forms a right angle triangle with the centre, with chord being the hypotenuse

Chord² = r² + r²

Chord² = 2r²

Chord = r√2