Question

A regular pentagon PQRST and a square PQBA are formed on opposite sides of PQ. Find ∠QRB

Answer 1

Answer:

∠ABN=90o∠ABC=108o∠MBC=360o−90o−108o=162o∠BMC+∠MBC+∠BCM=180o∠BMC+∠BCM=180o−162o=18o∠BMC=18o−∠BCM

But, ∠BCM=∠BMC

2∠BCM=18o∠BCM=9o

A