Question

The perimeter of an isosceles triangle is $54\text{units}$. The length of two equal sides of the triangle is $15\text{units}$ each. What is the length of the third side?

• A. $15\text{units}$
• B. $24\text{units}$
• C. $18\text{units}$
• D. $22\text{units}$

Answer 1

The correct option is B $24\text{units}$

A) $24\text{units}$

Perimeter of the isosceles triangle $=54\text{units}$
Length of the equal side of the triangle $=15\text{units}$
Total length of the two sides of the triangle $=15\text{units}+15\text{units}=30\text{units}$

Length of the unequal side of the triangle $=54\text{units}-30\text{units}=24\text{units}$