Page 112 - Start Up Mathematics_6

5. A quadrilateral with exactly one pair of parallel sides is:
(a) a square (b) a rhombus (c) a kite (d) a trapezium
6. A scalene triangle cannot be:
(a) an acute-angled triangle (b) an obtuse-angled triangle
(c) a right-angled triangle (d) an equilateral triangle
7. An obtuse-angled triangle can be:
(a) right-angled (b) equilateral (c) isosceles (d) none of these

solve Mentally

True or False
1. An obtuse right-angled triangle does not exist.
2. A pair of adjacent edges of a cuboid are perpendicular.
3. All the angles of an obtuse-angled scalene triangle are greater than 90°.
4. A cuboid is an example of a prism.
5. A tetrahedron is an example of a pyramid.

Fill in the Blanks
1. A triangle in which all the sides are equal is known as an ____________ triangle.
2. A polygon having 5 sides is called a ____________.
3. A bicycle has 20 spokes, the angle between a pair of adjacent spokes is ____________.
4. A quadrilateral having 2 pairs of adjacent sides equal and opposite sides unequal is known
as ____________.
5. Two faces of a cuboid intersect to form an ____________.
Answer in One Word or a Line

1. How many diagonals does a quadrilateral have?
2. How many points does a line segment consists of?
3. What is the measure of 2 right angles? Is it equal to a straight angle?
4. How many edges does a triangular prism have?
5. Is a trapezium with a pair of opposite sides parallel and equal a parallelogram?

let’s evaluate
1. How many line(s) may pass through the following:

(a) one point (b) two points (c) any three points (d) three collinear points
2. Is it possible to find the midpoint of a line? Give reasons to support your answer.
3. How many right angles do you make if you start facing
(a) north and turn clockwise towards west?
(b) east and turn anti-clockwise towards east?

(c) south and turn clockwise towards west?
(d) east and turn towards west?
4. Find the number of right angles turned by the hour hand of a clock when it goes from:
(a) 12 to 6 (b) 5 to 8 (c) 6 to 3
5. Draw a line segment AB measuring 8 cm. Take any point C between A and B such that
AC = 3 cm. Measure CB. Is AB = AC + CB?

104