Question

MB and NB are bisectors of ∠CBA and ∠ABD respectively. Find the value of ∠MBN in degrees.

Answer 1

Given that MB bisects ∠CBA and NB bisects ∠ABD.

So, ∠ABM=1/2 of ∠CBA and ∠ABN=1/2 of ∠ABD.

∠MBN= ∠ABM + ∠ABN
∠MBN=1/2 of ∠CBA+ 1/2 of ∠ABD
∠MBN=1/2 {∠CBA+∠ABD)
∠MBN=1/2 {∠CBD}
∠MBN=1/2 {180⁰} (Linear pair)
∠MBN=90⁰.

Therefore, the value of ∠MBN is 90⁰.