Tickbox Quiz #10, Q25: Can we solve for AD here by using the 30-60-90 degree triangle rule twice? (Since angle A is 60, D = 30, and B = 90)

[user6197]

[gregmat]

Yeah, let’s say you use 30-60-90 to solve for AB and BC. So AB is 5sqrt(3) and BC is 5. You can then use 30-60-90 for triangle ABD. We know AB is 5sqrt(3), so that means AD is double that, so 10sqrt(3) and BD is 15.