The area of a triangle is cm² and its sides are in the ratio 5 : 7 : 8. What is its perimeter?
Options
A
30 cm
B
40 cm
C
60 cm
D
70 cm
Answer & Analysis
Answer
B
Analysis
Question Analysis
Given the area of a triangle is cm² and its sides are in the ratio , the goal is to find the perimeter. Represent the sides using a common variable, apply Heron’s formula to relate the area to the variable, and solve for the perimeter.
Key Concept Explanation
Heron’s Formula: For sides , area , where .
Ratio Representation: Express sides as to simplify calculations with the given ratio.
Step-by-Step Solution
1. Represent sides using the ratio:
Let the sides be , , .
Perimeter , so semi-perimeter .
2. Apply Heron’s formula to find
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