Hello again!
Slow internet. Cluttered laptop. Hence the terrible delay.
This clip explains some properties of triangles using a lot of trigonometry.
This clip explains some properties of triangles using a lot of trigonometry.
I will explain the final step here. My phone was really
troubling me with that.
After substitution, use the identity sin2A + cos2A
= 1
Then you will get DN2= a2/4sin2A
Therefore DN = a/2sinA, which is equal to R.
