In the first rhombus, angle A is 60 degrees, and the diagonal BD is 25. Find the perimeter of the rhombus.

Solution:

• Since the angle A of the rhombus is 60 degrees and all sides of a rhombus are equal, triangle ABD is an isosceles triangle.
• Because angle A is 60 degrees, triangle ABD is equilateral, which means AB = AD = BD.
• However, the problem states that BD = 25. This implies that the side length of the rhombus is 25.
• The perimeter of a rhombus is 4 times the length of one side.
• Perimeter = 4 * side length = 4 * 25 = 100.

Answer: The perimeter of the rhombus is 100.