If the exterior angle of a regular polygon is 72°, then what is the number of sides of the polygon?
If the interior angle of a regular polygon is 144°, then what is the number of its sides?
In the figure, PQRS is a parallelogram. Find the values of x, y and z.
Using the property, 'Opposite angles of a parallelogram are equal', we have: z =
Since, sum of all the angles of parallelogram =
∴ 2z + 2x =
or 2 () = 2x =
or
or 2x =
or x =
Now,
y+z = (Liner pair)
or, y+
∴ y =
Thus, x=
y=
x=
Take two identical set squares with angles 30°-60°-90° and place them adjacently to form a parallelogram as shown in Figure. Does this help you to verify the above property?
Take two identical 30°-60°-90° set-squares and form a parallelogram as before. Does the figure obtained help you to confirm the above property?