∠ACD is an exterior angle of ∆ABC. The measures of ∠A and ∠B a

1.	∠ACD is an exterior angle of ∆ABC. The measures of ∠A and ∠B are equal. If m∠ACD = 140°, find the measures of the angles ∠A and ∠B.
Answer» Let the measures of ∠A be x°. m∠A = m∠B = x° ∠ACD is the exterior angle of ∆ABC ∴ m∠ACD = m∠A + m∠B ∴ 140 = x + x ∴ 140 = 2x ∴ 2x = 140 ∴ x = 140/2 = 70 ∴ The measures of the angles ∠A and ∠B is 70° each.

∠ACD is an exterior angle of ∆ABC. The measures of ∠A and ∠B are equal. If m∠ACD = 140°, find the measures of the angles ∠A and ∠B.

Answer»

Let the measures of ∠A be x°.

m∠A = m∠B = x°

∠ACD is the exterior angle of ∆ABC

∴ m∠ACD = m∠A + m∠B

∴ 140 = x + x

∴ 140 = 2x

∴ 2x = 140

∴ x = 140/2

= 70

∴ The measures of the angles ∠A and ∠B is 70° each.