Question

please say me the answer by step by step

Answer 1

Answer:

60°

Step by step:

∵ ∠HCD is a straight angle

∴ m∠BCD = 180-m∠BCH

m∠BCD = 180-35

m∠BCD = 145

EDCB is a quadrilateral

∵ Sum of all interior angles of quadrilateral = 360°

∴ m∠EBC = 360 - ( m∠BED + m∠EDC + m∠BCD)

m∠EBC = 360 - ( 105 + 50 + 145 )

m∠EBC = 360 - 300

m∠EBC = 60°

∵ ∠ABF and ∠EBC are vertically opposite angles

∴ m∠ABF = m∠EBC

m∠ABF = 60°

Answer 2

angle DCB = 180° - 35°= 145

so let angle EBC = x

therefore.

$145 + 50 + 105 + x = 360 \\ 300 + x = 360 \\ x = 360 - 300 \\ = 60$

As EBC =ABF (vertically opposite angle)

so angle ABF = 60°