Question

Find each one of the lettered angles giving Type 1: On alternate Angles give reasons :​

Answer 1

Step-by-step explanation:

70=b (vertically opposite angles)

70+70+x=180 (straight line)

x=40

x+40+a=180(angle sum property)

40+40+a=180

80+a=180

a=100

•: a=100 b=70

x=40

Answer 2

In the given figure ,

∠ b = 40°. [Alt. Angle]

Now, let the angle third angle of triangle be x

70° + ∠b + ∠x = 180° [ Linear pair ]

∠x = 180° - (70° + 40°)

∠x = 70°

Sum of all angle of Triangle is 180°

∠a + 70° + 40° = 180°

∠a = 70°

Also,

∠a = 70° [Alt. Angle]