Question

Work out the size of AED. Work out x

Answer 1

Answer:

a). m∠AED = 70°

b). x = 10°

Step-by-step explanation:

a). Quadrilateral ABDE is a cyclic quadrilateral.

Therefore, by the theorem of cyclic quadrilateral,

Sum of either pair of opposite angle is 180°

m(∠AED) + m(∠ABD) = 180°

m(∠AED) = 180° - 110°

m(∠AED) = 70°

Since, ∠AED ≅ ∠EAD

Therefore, m∠AED = m∠EAD = 70°

b). By triangle sum theorem in ΔABD,

m∠ABD + m∠BDA + m∠DAB = 180°

110° + 40° + m∠DAB = 180°

m∠DAB = 180° - 150°

m∠DAB = 30°

m∠BAE = m∠EAD + m∠BAD

              = 70° + 30° = 100°

By angle sum theorem in ΔACE,

m∠EAC + m∠AEC + m∠ACE = 180°

100° + 70° + x° = 180°

x = 180° - 170°

x = 10°