A square pyramid has a total surface area of 340 cm² and a slant height of 12 cm. What is the length of its base side?
Options
A
5 cm
B
8 cm
C
10 cm
D
12 cm
Answer & Analysis
Answer
D
Analysis
Question Analysis
This reverse-calculation problem tests algebraic manipulation of surface area formulas.
Key Concept Explanation
The TSA formula for square pyramids can be rearranged to solve for base side length.
Step-by-step explanation
TSA = base area + lateral area
340 = s² + 2 × P × 12 = s² + 2 × 4 × s × 12
Simplify equation:
s² + 24s - 340 = 0
We need to find two numbers that multiply to - 340 and add up to 24.
We can write and .
So, .
Set each factor equal to zero:If
Want More Practice Questions?
Access thousands of practice questions with detailed explanations on Scholardog.