Page 144 - Math Smart - 7
P. 144
Q Lines and CH are straight lines.
Solve for a and b.
4if + w
Sum of angles in a quadrilateral
A quadrilateral is a closed shape that has four sides, four vertices and four interior
angles. The sides of a quadrilateral are straight lines.
We have learnt that the sum of angles in a triangle is 180°. What about in a
quadrilateral?
Let us find out what is the sum of the angles in a quadrilateral.
O Draw and cut out the quadrilaterals shown below. Draw a diagonal that
A diagonal is a line from
cuts the quadrilateral into triangles.
one vertex of a polygon
to the opposite vertex
in the polygon. It cuts a
quadrilateral into two
triangles.
Q How many diagonals did you draw?
Quadrilateral A Quadrilateral B
Q Name each angle inside the quadrilaterals.
Angles and Their Properties
I
