Page 160 - New Medley 5 Semester 2

EXERCISE 7.2

A. Can a triangle have following measures of angles?

1. 33°, 67°, 80° 2. 90°, 90°, 0° 3. 100°, 60°, 10°

4. 75°, 85°, 20° 5. 105°, 110°, 25° 6. 40°, 50°, 60°

B. Find the missing angle of each of the following.
1. D 2. A 3. X 4. L

? ? ?
40° 30° 60°
E F 70° 30°
C 90° 45°
B 80° ?
M N
Y Z
C. Can it be possible to form a triangle with the given measures of sides?

1. 18 cm, 18 cm, 18 cm 2. 6 cm, 6 cm, 15 cm

3. 12 cm, 15 cm, 9 cm 4. 4 cm, 5 cm, 8 cm

5. 3 cm, 5 cm, 10 cm 6. 8 cm, 4.5 cm, 3.5 cm

D. 1. The measures of two angles of a triangle are 25° and 50°. Find the
measure of third angle and classify the triangle on the basis of sides
as well as angles.

2. The measures of two angles of a triangle are 30° and 60°. Find the
measure of third angle. What kind of a triangle is it?

3. A right-angled triangle has two angles of equal measure. Find the angles

and give other name of the triangle.

4. A triangle has all the angles of equal measure. Find the angles and

name the triangle in two different ways.
E. The perimeter of a triangle is 30 cm. Can the triangle have two sides 3 cm and
15 cm? Justify your answer.

Quadrilaterals

A quadrilateral is a four-sided polygon. A quadrilateral has four sides and

four angles. There are four vertices of a quadrilateral. The line segments
that join opposite vertices are called its diagonals.

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