Question

which is necessary to calculate the perimeter of a triangle?
a. the area of the triangle
b. the length of all three sides
c. the base of the triangle
d. the height of the triangle

Explanation:

The perimeter of a triangle is the sum of the lengths of its sides. The area formula \(A = \frac{1}{2}\times base\times height\) (options a, c, d) is for calculating area, not perimeter. Only knowing the lengths of all three sides (option b) allows us to compute \(Perimeter=a + b+ c\) (where \(a\), \(b\), \(c\) are side - lengths).

Answer:

B. The length of all three sides