Answer:
The length of each side is 26.3 cm
Step-by-step explanation:
Opposite sides of an isoceles triangle are equal
The isoceles triangle is divided into 2 right-angled triangles so the length of one side can be calculated using trigonometric ratio
When the isoceles triangle is divided, the angle in the right-angled triangle is 20° (1/2 of 40°) and the base is 9cm (1/2 of 18 cm), the hypotenuse side is calculated using trigonometric ratio
Let the length of the hypotenuse side be y
9/y = sin 20°
y = 9/0.3420 = 26.3
Length of each side is 26.3 cm
