Question

The perimeter of an isosceles triangle is $3\frac{9}{4}$ cm. The base of an isosceles triangle is $\frac{3}{2}$ cm. What is the length of either of the remaining equal sides?

• A. $\frac{15}{4}$ cm
• B. $\frac{15}{8}$ cm
• C. $\frac{8}{15}$ cm
• D. $\frac{4}{15}$ cm

Answer 1

The correct option is B $\frac{15}{8}$ cm

Perimeter = $3\frac{9}{4}=\frac{21}{4}$ cm

Property of an isosceles triangle = two sides are equal

Perimeter of triangle = Sum of three sides
$\therefore \frac{21}{4}=a+a+\frac{3}{2}$

$⟹2a=\frac{21}{4}-\frac{3}{2}$

$⟹2a=\frac{21-6}{4}$

$\therefore a=\frac{15}{8}$