What is the total surface area of a cylinder with radius 2cm and height 1.5cm, correct to 2 significant figures?

Analyze the question: We need the total surface area of a closed cylinder with r = 2 cm and h = 1.5 cm, rounded to 2 significant figures.

Concept: Total surface area = curved surface + two circular ends

TSA = 2πrh + 2πr² = 2πr(h + r)

Solution:

• TSA = 2 × π × 2 × (1.5 + 2)
• TSA = 4π × 3.5
• TSA = 14π

Using π = 22/7: 14 × 22/7 = 44 cm²

Using π = 3.142: 14 × 3.142 = 43.99 ≈ 44 cm²

To 2 significant figures, the answer is 44 cm².

Tip: Remember "2πr(h + r)" for a closed cylinder. If the question says "open" cylinder, use only one end: 2πrh + πr². Also, when you see 14 with π = 22/7, the 7 cancels easily, which is a sign you are on the right track.