Page 15 - Cambridge IGCSE Mathematics Core and Extended

Test Yourself 11.3

1. For each of the following triangles, determine
whether it has line(s) of symmetry. Draw the (c) (d)

line(s) of symmetry for the triangles that 48° 28°
42°
have lines of symmetry. 56°
(a) (b)
5. Find the value of x in each of the following
triangles.

(a) 80° (b) 76°
(c) (d) x
45° x
28°

(c) x 30° (d) x
2. Draw each of the following triangles using 22° 124°
a protractor and a ruler.
x
(a) An equilateral triangle with sides 6 cm
each.
(b) An isosceles triangle with base 8 cm 6. Find the unknown angles marked in the
and base angles 58° each. following triangles.
(c) ∆KLM with KL = 6.4 cm, /LKM = 40° (a) (b)
and /KLM = 105°.
70°
(d) ∆PQR with PQ = 7.5 cm, PR = 8.4 cm
a
and /QPR = 50°. x
30°
(e) ∆XYZ with YZ = 5.6 cm, XY = 7.2 cm
and /XYZ = 60°.
(f) ∆ABC with AB = 8 cm, /BAC = 46° (c) (d)
and /ACB = 80°. (Hint: Determine the t
third angle in the triangle first.) 128° y
42°
3. Determine whether each of the following
triangles is an equilateral triangle, an
7. In each of the following triangles, find the
isosceles triangle or a scalene triangle.
value of x.
(a) (b)
(a) (b)
65°
70°
40° 60° x 72° x
(c) (d)

50° 130° (c) x (d) 38°
25° 80°
30° 28°
10°
4. Determine whether each of the following x
triangles is an acute-angled triangle, an (e) (f)
obtuse-angled triangle or a right-angled 46° 62°
triangle. 34° x 45°
(a) (b) x
50°
(g) 114° (h) x 67°
44°
47°
x 46°
32° 20°

Chapter 11 Polygons I 155

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