Download Properties of Triangles - MoreMaths

Mathematics
Class 7
Properties of Triangles
Q1)
State which of the following statements are true or false:
(1 Mark)
Every isosceles triangle is an acute-angled triangle.
a)
b)
c)
d)
Q2)
True
False
Can't say
None of these
Fill in the blanks:
(1 Mark)
------- angles of an isosceles triangle are equal.
a)
b)
c)
d)
Q3)
In a right triangle, the sum of the two acute angle is -------°.
a)
b)
c)
d)
Q4)
One
Two
Three
None of these
45
360
90
180
In a triangle there are ------ angles.
a)
b)
c)
d)
(1 Mark)
(1 Mark)
2
3
4
6
Q5)
(1 Mark)
The value of a in the figure is ---------.
a)
b)
c)
d)
40°
90°
60°
None of these
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Mathematics
Class 7
Q6)
Fill in the blanks:
(2 Marks)
Angle opposite to equal sides of a triangle are also -------.
Q7)
An exterior angle of a triangle is equal to the sum of the two ---------------- angles.
(2 Marks)
Q8)
Congruent angles are angles which have -------------- angle sizes.
(2 Marks)
Q9)
Find the third angle of the following triangles:
(4 Marks)
a. 40° + 50° + ----- = 180°
b. 90° + 20° + ----- = 180°
c. 45° + 60° + ----- = 180°
d. 110° + 30° + ----- = 180°
Q10)
The given below are the measurements of the sides of (5, 12, 13) triangles. Fill in the
missing measurements:
(3 Marks)
a. 15 cm, ------, 39 cm
b. 25 cm, 60 cm, -----c. ------, 6 cm, 6.5 cm
Q11)
The angles of a triangle are in the ratio of 1 : 2 : 3. Find the angles.
Q12)
(3 Marks)
(2 Marks)
Q13)
The exterior angle of a triangle is 135°. If one of the opposite interior angles is 65°, find
the another opposite interior angle.
(2 Marks)
Q14)
A ladder 8.5 m long is leaning against a wall. Its foot is 4 m from the foot of the wall.
How far up the wall does the ladder reach?
(2 Marks)
Q15)
If the hypotenuse of a right-angled triangle is 25 cm and one of the sides is 15 cm, find (3 Marks)
the third side and hence the perimeter and area of the triangle.
Q16)
Correct the following statements:
If one of the angles if a triangle is greater then the sum of the other two angles, than
the triangle is an acute-angled triangle.
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(2 Marks)
Mathematics
Class 7
Q17)
State whether the following measures (in cm) represent the sides of a triangle-8 cm, 10 (2 Marks)
cm, 6 cm. Give reasons to justify your answer.
Q18)
Check if the following measurement will form a triangle.
(2 Marks)
110°, 30° and 40°
Q19)
The sides of a triangle are 15 cm, 36 cm and 39 cm. Check if it is a right-angled triangle. (2 Marks)
Q20)
In a right-angled triangle, one of the acute angles is the complement of the other
acute angle. Find the angles of the triangle.
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(2 Marks)
Mathematics
Class 7
Answers
Q1)
True
Q2)
Two
Q3)
90
Q4)
3
Q5)
40°
Q6)
Equal
Q7)
Interior opposite or remote interior
Q8)
Equal
Q9)
a. 90°
b. 70°
c. 75°
d. 40°
Q10)
a. 36 cm
b. 65 cm
c. 2.5 cm
Q11)
30°, 60°, 90°
Q12)
It is not right angled triangle
Q13)
135° - 65° = 70°
Q14)
7.5 m
Q15)
Q16)
The triangles is an obtuse-angled triangle
Q17)
Yes, the sum of any two sides of a rectangle greater than the third side
Q18)
Yes
Q19)
Yes
Q20)
x = 45°
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