Let’s Practise
1 Write the letters of the two impossible triangles. They have not been drawn accurately.
100°
100°
25°
25°
30°
50°
A
B
60°
70°
90°
60°
60°
50°
C
D
Riana has drawn a triangle and measured two of the angles. She thinks that the missing angle b must be 70°. Is she correct? Check her answer using two different methods. Measure each angle in this triangle using a protractor. Complete the statement:
2
b
c
a 30°
3
b
+ = (angle a) (angle b) (angle c) +
a
c
74
SK_G5_SB_06_066-077.indd 74
01/12/2021 15:00
Made with FlippingBook Learn more on our blog