Perimeter of a semicircle (radius = 28 cm) Find the perimeter of a semicircle of radius 28 cm (use perimeter = πr + 2r).

Introduction / Context:The boundary length of a semicircle includes the curved arc plus the diameter. The standard formula is Perimeter = (1/2 of circumference) + diameter = πr + 2r.

Given Data / Assumptions:

• Radius r = 28 cm
• Use π = 22/7 for exact integer outcomes.

Concept / Approach:Compute the arc component πr and add the straight diameter 2r. Avoid using the full circumference 2πr, since we only have half the circle plus the diameter.

Step-by-Step Solution:

Verification / Alternative check:Using π ≈ 3.14 gives 3.14*28 + 56 ≈ 87.92 + 56 ≈ 143.92, rounding to 144, consistent with exact form.

Why Other Options Are Wrong:288 doubles the arc; 121 and 242 are unrelated to πr + 2r with r = 28 cm; only 144 matches.

Common Pitfalls:Forgetting to include the diameter or mistakenly halving 2πr to πr and then halving again causes errors.

Final Answer:144