Triangle

Q. How many vertices does a triangle have?

1. 1
2. 2
3. 4
4. 3

Q. How many diagonals does a triangle have?

1. 1
2. 0
3. 2
4. None of the above

Q. A ladder 13 m long is placed on the ground in such a way that it touches the
top of a vertical wall 12 m high. Find the distance of the foot of the ladder
from the bottom of the wall.

1. 4 m
2. 5 m
3. 3 m
4. 7 m

Q. A triangular region can be defined as

1. The boundary and interior of a triangle.
2. The boundary and interior of a figure.
3. The boundary and exterior of a triangle.
4. The boundary and interior of a polygon.

Q. How many angles does a triangle have?

1. 1
2. 4
3. 2
4. 3

Q.

How many triangles are there in the following figure?

1. Six

2. Three

3. Five

4. Four

Q. What is the name of the regular polygon with all 3 sides of the same length?

1. Triangle
2. Pentagon
3. Square
4. Equilateral triangle

Q. If all the three sides of a triangle are of different lengths, then the triangle is called a ___________ triangle.

1. isosceles
2. equilateral
3. acute angled
4. scalene

Q. The line segments forming a polygon are called _________________.

1. sides
2. vertices
3. angles
4. curves

Q. How many sides does a triangle have?

1. 4
2. 2
3. 3
4. 5

Q. The polygon with the least number of sides is:

1. A line segment
2. An angle
3. A triangle
4. A square

Q.

6. Identify the true and false statements:

(ii) No three vertices of a quadrilateral are collinear.

1. True
2. False

Q.

Do triangles have opposite angles?

Q. In obtuse angled triangle, each angle is more than ${90}^{\circ }$.

1. True
2. False

Q. Which points are lying in the exterior of the triangle?

1. P
2. S
3. U
4. M

Q.

Question 1:

Draw a rough sketch of a triangle ABC. Mark a point P in its interior and a point Q in its exterior. Is the point A in its exterior or in its interior?

Q.

An equilateral triangle is also an acute-angled triangle.

1. True
2. False

Q. How many triangles are in the given figure?

1. 12
2. 8
3. 10
4. 14

Q.

Identify the number of triangles in the given figure:

1. 4

2. 6

3. 5

4. 3

Q.

Name the type of the triangle.

$∆XYZwithXY=YZ$

Q.

What are the $6$ types of triangles?

Q. The boundary which is made up of both curved and straight lines is called Curvilinear boundary. Say True or false?

1. Blue region
2. Red region

Q.

State whether the statement is true or false.
A triangle can have all the three angles greater than ${60}^{\circ }$.

1. True

2. False

Q.

Which of the following triangles has three equal sides?

1. Right angled triangle

2. Uneven triangle

3. Scalene triangle

4. Equilateral triangle

Q.

Question 14
In the given figure, AB=BC and AD =BD = DC.

The number of isosceles triangles in the figure is
a) 1
b) 2
c) 3
d) 4

Q.

Investigate: Use strip and fasteners to make a triangle and a quadrilateral. Try to push inward at any one vertex of the triangle. Do the same to the quadrilateral. Is the triangle distorted? Is the quadrilateral distorted? Is the triangle rigid? Why is it that structures like electric towers make use of triangular shapes and not quadrilateral?

Q. A triangle is a polygon with 4 sides.

1. True
2. False

Q.

Name a triangle whose all sides are unequal.

Q. The angles of a triangle are in the ratio 3: 4: 5. The triangle is:

1. an obtuse angled triangle
2. an acute angled triangle
3. a right triangle
4. an isosceles triangle

Q.

Question 57

What is common in the following figures (i) and (ii)?

Is figure (i) that of triangle? If not, why?