Page 308 - Math Smart - 7

In this chapter

Pupils should be able to: CHAPTER 14.2
• use a ruler, set square
and protractor to
construct squares and Construct! hg Polygons
rectangles
• use a ruler, set square
and protractor to
construct a triangle 14.2.1 Constructing squares and
given two sides and the
included angle (SAS) rectangles
• use a ruler, set square
and protractor to
construct a triangle Constructing squares
given two angles and
You can use a ruler, a set square and a protractor to construct a square.
the included side (ASA)
Remember that a construction is an accurate drawing.
• use a ruler, set square
and protractor to
construct regular Example 1
polygons, given a side
and the internal angle
Construct square ABCD that has side lengths of 70 mm.
Solution
Draw a sketch to help you.
Use your ruler. Draw a line segment that is 70 mm long.
D
J L 1 This is one side of the square.
70 mm
"1 r 1 impiii iin|U(i
70 mm
si 6

RECALL Place the centre of your protractor
at one end of the line segment.
Use a protractor to draw
the following angles. Measure 90° and make
a construction mark.
a) 32° b) 90°
c) 141° d) 206°

Place the centre of your
5 protractor at the other
end of the line segment.

Measure 90° and make
a construction mark.

UNIT 14 I Geometrical Constructions