A figure is made of an arrowhead and a parallelogram. The arrowhead has two equal sides. The parallelogram shares one side with the arrowhead. A diagonal of the parallelogram is equal to its sides. An

Step 1: Identify the shapes and given information.
The figure consists of an arrowhead and a parallelogram joined together.

• The arrowhead has two equal sides, indicated by single dashes. Let their length be $s$.
• The parallelogram shares one of these sides with the arrowhead, so this side also has length $s$.
• A diagonal of the parallelogram is drawn, and it is also marked with a single dash, meaning its length is $s$.
• The problem states that an equilateral triangle is formed using this diagonal. This means the triangle formed by the diagonal and two sides of the parallelogram is equilateral. Let the parallelogram be $CDEF$, where $CD$ is the shared side. The diagonal is $CE$. The equilateral triangle is $\triangle CDE$.