Difficulty: Easy
Correct Answer: 21.63
Explanation:
Introduction / Context:The Pythagorean theorem is widely used across electrical engineering and physics, particularly in phasor magnitude calculations (e.g., combining orthogonal voltage or current components). Here, it is applied directly to a geometric right triangle to find the hypotenuse from two perpendicular legs.
Given Data / Assumptions:
Concept / Approach:Use the Pythagorean relation c^2 = a^2 + b^2. Then compute c = √(a^2 + b^2). This is the same vector magnitude formula used in phasor addition and impedance magnitude calculations in AC circuits.
Step-by-Step Solution:
Compute squares: a^2 = 12^2 = 144, b^2 = 18^2 = 324.Sum: a^2 + b^2 = 144 + 324 = 468.Take square root: c = √468.Simplify numerically: √468 ≈ 21.633 (since 21.633^2 ≈ 468).Rounded to two decimals: c ≈ 21.63.Verification / Alternative check:Express √468 = √(4 * 117) = 2√117. With √117 ≈ 10.8167, c ≈ 2 * 10.8167 ≈ 21.633, which matches the decimal computation and ensures consistent rounding.
Why Other Options Are Wrong:
Common Pitfalls:
Final Answer:21.63
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