Page 58 - Mathematics Coursebook

5.2 Drawing and measuring angles

2 Draw angles of the following sizes.
a 62° b 157° c 200° d 295° e 19° f 111° g 342° h 233°
3 a Measure the angles labelled x°, y° and z°.
When we use small italic letters to
label angles, each letter stands for
a number of degrees.

x°
z°
y°

b Explain why the angles should add up to 360°. Use this fact to check your accuracy.
4 a Measure the angles labelled r°, s° and t°.
b The angles should add up to 900°. Use this fact to check your accuracy.

s°

r°

t°

c If the triangle was equilateral, what would be the values of r, s and t? Give a reason
for your answer.

5 The angles of a triangle are 125°, 37° and 18°.
a What are the reflex angles at the corners of this triangle?

b Can you draw a triangle where one of the angles of the triangle is a reflex angle?

5 Angles 57