Question

5. Find the unknown marked angle. ​

Answer 1

Step-by-step explanation:

i ) So as you can see this figure is making two triangles

So we can get the second triangle angles.

Lets see second triangle,

Angle B = 121 degrees

Angle C = ?

Angle A = ?

Angle C = 43 degrees (Alternative Angles)

So now we can find Angle A by Angle Sum property

Angle A + Angle B + Angle C = 180

Angle A + 121 + 43 = 180

Angle A + 164 = 180

Angle A = 180 - 164

Angle A = 16 degrees

ii ) Now we'll find Angle D

So now as we can see the figure is parallelogram.

And properties of parallelogram says that its opposite angles are equal and adjacent angles make sum of 180.

Now lets see first triangle.

Let 43 degree angle be named as Angle E

And let the third angle be F.

Angle E = 43

Angle D = ?

Angle F = ?

Angle F = 16 degrees (Alternative Angles)

Now by Angle Sum Property we will find third angle.

43 + 16 + Angle D = 180

59 + Angle D = 180

Angle D = 180 - 59

Angle D = 121