Practical Geometry MCQ Test — Class 6 ICSE

Solution:

A compass is a geometrical instrument with two arms.

One arm has a sharp point that is placed at the centre, and the other arm holds a pencil to draw the circle.

Therefore, a compass is used to draw a circle of a given radius.

Solution:

A protractor is a semi-circular instrument marked with degrees from 0 to 180.

It is used to measure and construct angles of given measures.

Solution:

To construct a line segment of a given length, we use a ruler to measure the required length.

We then use a compass to mark off the exact length on a line.

Therefore, the essential pair is ruler and compass.

Solution:

To copy a line segment AB, the first step is to draw any line l and mark a point P on it.

Then we set the compass to the length AB and draw an arc from P on line l to get point Q.

PQ is then the required copy of AB.

Solution:

A perpendicular bisector is a line that is perpendicular to a segment and passes through its midpoint.

Since it passes through the midpoint, it divides the segment into two equal parts.

Solution:

A perpendicular bisector is perpendicular to the line segment.

Perpendicular lines meet at right angles, which means they form a 90-degree angle.

Solution:

Draw a ray OA. With centre O, draw an arc cutting OA at point P.

With the same radius and centre P, draw another arc cutting the first arc at point Q.

Join OQ. Angle AOQ = 60 degrees.

This works because OPQ forms an equilateral triangle, so each angle is 60 degrees.

Solution:

An angle bisector is a ray that divides an angle into two equal parts.

If the original angle is 80 degrees, each part after bisection is 40 degrees.

Solution:

A right angle measures 90 degrees.

When bisected, each part = 90 / 2 = 45 degrees.

Solution:

A divider has two arms, both ending in sharp points.

It is used to compare lengths of line segments and to transfer measurements.