Calculate the size of one red angle.
30°
The triangle is isosceles so the two red angles are the same. Two red angles + 30 = 180. Two red angles = 150. One red angle = 75.
1 Find the size of the blue angle in each diagram.
30°
15°
60°
(b)
(c)
(a)
80°
30°
55°
2 Find the size of the green angle in each diagram.
110°
30°
(b)
(a)
162
9781380050717__text.indb 162
28/04/2022 12:13
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