Page 79 - Maths Class 06

x = 20 °
´
\ 4x = 4 20 ° = 80 °
Thus, the angles of the triangle are 20°, 80° and 80°.

Exercise 5.4

1. Classify the following triangles on the basis of their angles:
(a) 70°, 70°, 40° (b) 30°, 110°, 40° (c) 30°, 30°, 120° (d) 90°, 45°, 45°
2. Name the following triangles in two different ways:

(a) (b)

2.3 cm 2.3 cm

90°

2.3 cm
(c) (d)

6 cm 12 cm
10 cm

6 cm 8 cm

3. The obtuse angle of the obtuse angled isosceles triangle is 130°. Find the other two angles.
P

4. Find ÐPRQ in the given figure, if ÐRPQ = RQP = 45 °.

Q R S
5. The three sides of an equi lat eral trian gle are equal and the three angles are also equal. What is the
measure of each of the angle in equilateral trian gle? Why?
6. Can a triangle have two right angles? Explain your answer.
7. Find the measure of the angles marked by x in the following:

(a) D (b)

C

x° x° 60°
75°
B A

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