In triangle ΔABC, ∠C is a right angle and CD is the altitude to AB . Find the measures of the angles of the ΔCBD and ΔCAD if: Chapter Reference a m∠A = 20°

1. ∆CBD:      ∠B = 70°; ∠BCD = 20°; ∠ BDC = 90°

2. ∆CDA: ∠ACD = 70°;      ∠A = 20°; ∠ ADC = 90°

Step-by-step explanation:

1. ∆DBC

In ∆ABC

 ∠A + ∠B + ∠C = 180°

20° + ∠B + 90 ° = 180°

         ∠B + 110 ° = 180°

      ∠DBC = ∠B =  70°

In ∆CBD

                      ∠BDC =  90°

∠B + ∠BCD + ∠CBD = 180°

  70° + ∠BCD + 90 ° = 180°

           ∠BCD + 160° = 180°

                        BCD =   20°

2. ∆CAD

∠A + ∠ACD + ∠ADC = 180°

   20° + ∠ACD + 90° = 180°

            ∠ACD + 110° = 180°

                      ∠ACD =   70°