The triangle (triângulo) is a small idiophone instrument made of iron or steel.
It arrived in Brazil via the Portuguese culture and spread far and wide throughout northeastern pop music, where it is also known as the tengo-lengo. It is played with a small metal stick, in sync with the other hand, which holds the triangle up and alternates between open and closed sounds by opening and closing the hand.
In the past, small metal washers were placed on the triangle to allow for other bright sounds, which were produced by the washers when the metal was hit and began to vibrate. The classic northeastern trio is made up of a zabumba, a sanfona (accordion), and a triangle, three components that are essential to a forró, as well as the baião, xaxado and xote rhythms.
In Bahia, the triangle is found in some regions with samba de roda, though it is mainly found in the hands of taboca (a cone-shaped cookie) street vendors.