Respuesta :
Given :
- ZC = 90°
- CD is the altitude to AB.
- [tex]\angle[/tex]A = 65°.
To find :
- the angles in △CBD and △CAD if m∠A = 65°
Solution :
In Right angle △ABC,
we have,
=> ACB = 90°
=> [tex]\angle[/tex]CAB = 65°.
So,
=> [tex]\angle[/tex]ACB + [tex]\angle[/tex]CAB+[tex]\angle[/tex]ZCBA = 180° (By angle sum Property.)
=> 90° + 65° + [tex]\angle[/tex]CBA = 180°
=> 155° +[tex]\angle[/tex]CBA = 180°
=> [tex]\angle[/tex]CBA = 180° - 155°
=> [tex]\angle[/tex]CBA = 25°.
In △CDB,
=> CD is the altitude to AB.
So,
=> [tex]\angle[/tex] CDB = 90°
=> [tex]\angle[/tex]CBD = [tex]\angle[/tex]CBA = 25°.
So,
=> [tex]\angle[/tex]CBD + [tex]\angle[/tex]DCB = 180° (Angle sum Property.)
=> 90° +25° + [tex]\angle[/tex]DCB = 180°
=> 115° + [tex]\angle[/tex]DCB = 180°
=> [tex]\angle[/tex]DCB = 180° - 115°
=> [tex]\angle[/tex]DCB = 65°.
Now, in △ADC,
=> CD is the altitude to AB.
So,
=> [tex]\angle[/tex]ADC = 90°
=>[tex]\angle[/tex] CAD =[tex]\angle[/tex] CAB = 65°.
So,
=> [tex]\angle[/tex]ADC + [tex]\angle[/tex]CAD +[tex]\angle[/tex]DCA = 180° (Angle sum Property.)
=> 90° + 65° + [tex]\angle[/tex]DCA = 180°
=> 155° +[tex]\angle[/tex]DCA = 180°
=> [tex]\angle[/tex]DCA = 180° - 155°
=> [tex]\angle[/tex]DCA = 25°
Hence, we get,
- [tex]\angle[/tex]DCA = 25°
- [tex]\angle[/tex]DCB = 65°
- [tex]\angle[/tex]CDB = 90°
- [tex]\angle[/tex]ACD = 25°
- [tex]\angle[/tex]ADC = 90°.