Question

what is the justification for 90 degree angle

Answer 1

straight angle i hope this will help u

Answer 2

Answer:

Justification

To prove ∠POA = 90°

To prove this, draw a dotted line from the point O to C and O to D and the angles formed are:

From the construction, we note that

OB = BC = OC

Hence, OBC is an equilateral triangle

So that, ∠BOC = 60°.

Likewise

OD = DC = OC

Hence, DOC is an equilateral triangle

So that, ∠DOC = 60°.

From SSS triangle congruence rule

△OBC ≅ OCD

So, ∠BOC = ∠DOC [By C.P.C.T]

Hence, ∠COP = ½ ∠DOC = ½ (60°).

∠COP = 30°

To determine ∠POA = 90°:

∠POA = ∠BOC+∠COP

∠POA = 60°+30°

∠POA = 90°

Hence, Proved