Question

The perimeter of an isosceles triangle is equal to 2019 cm. If the length of its base = 519 cm, the find the length of each of the other (equal) sides of the triangle.

• A. 1500cm
• B. 750cm
• C. 800cm
• D. 1019cm

Answer 1

The correct option is B 750cm

$\text{Perimeter of an isosceles triangle = sum of its 3sides}$
We know that 2 of the sides an isosceles triangle are equal in length. Let each of these sides = a cm
Hence $\text{Perimeter of the triangle = 2a + base of the triangle}$.
P = $2019$ = $2\times a+519$
$\to$ $2019-519=1500=2a$
$\to$ $a=\frac{1500}{2}=750cm$
Hence each of the other 2 sides of the triangle = 750 cm