Recall that in a right triangle, sine is the ratio of the opposite side to the hypotenuse:
We are actually not given the opposite side in this case. However, since we know the hypotenuse and the adjacent side, we can use the Pythagorean Theorem to find the opposite side. So:
Let <em>a</em> be the adjacent side and <em>b</em> be the opposite side. <em>c</em> will be the hypotenuse.
Step-by-step explanation: Each triangle has 3 sides, and each side is 1 cm. Multiply the number of sides for one triangle by the total number of triangles. 3 x 40=120. The perimeter is 120 cm.