Page 24 - 新思维数学学生用书5 样章

2.1 Triangles

2 Name each type of triangle.

a b c

d e

3 a Use a pencil and ruler to sketch an isosceles triangle.
b Use a pencil and ruler to sketch a scalene triangle.

c Ask your partner to check the triangles you have drawn in parts a and b. Check
your partner’s triangles by tracing and comparing the sizes of the angles. Tell

your partner how you know if their triangles are isosceles and scalene.

Look at the triangles you have drawn. Think about how you drew
each triangle. Most people find that an equilateral triangle is more
difficult to draw. Try to draw an equilateral triangle. Think about why
it might be more difficult to draw.

4 Which of these triangles has an obtuse angle?
A B

C
D

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