Consider triangles ACM and BCM. In these triangles,
- given;
- definition of perpendicular lines CM and AB;
- reflexive property.
So,
by ASA postulate (if one side and two angles adjacent to this side of one triangle are congruent to one side and two angles adjacent to this side of another triangle, then two triangles are congruent).
It also means that a rhombus is formed from 2 identical equilateral triangles ( 2 identical 30 - 60 - 90 triangles forms one equilateral ) and a side of that triangle measures : 30 feet. Answer: The perimeter of the garden : 4 * 30 = 120 feet