Question

construct an isosceles triangle ABC whose base BC = 6 cm and each of the equal sides is equal to 4.5 cm. Draw AD | BC.

Answer 1

To draw the isosceles triangle of given measure follow the following steps:

1. Draw a base line of 6 cm and name it as BC.

2. Take a compass, open it to a radius of 4.5 cm. Now taking B as centre draw an arc above the line BC.

3. Then taking C as centre and radius of 4.5 cm draw an arc above line BC such that it cut the previous arc.

4. Mark the point as A at which the 2 arcs intersect.

5. Join AB and AC.

6.Now open the compass of arbitrary radius and taking B as centre draw 2 arcs above and below the line BC.

7. Then with the same arbitrary radius ,taking C as centre draw 2 arcs above and below the line BC such that they intersect the previous 2 arcs.

Mark the intersection points as X and Y.

8. Join X and Y.

9. Mark the point as D where XY intersects BC.

10. Here AD is perpendicular to BC.

You can cross check it using a protector.

Answer 2

an isosceles triangle ABC whose base BC = 6 cm and each of the equal sides is equal to 4.5 cm.

• Steps of construction:
• Draw a line BC with a scale of 6 cm.
• Now, from end points B and C draw arcs above the line BC with the scale of 4.5 cm.
• The point where these arcs meet, mark that point as A.
• Join AB and AC.
• Now, from end points B and C draw arcs below the line BC with the scale of 4.5 cm.
• The point where these arcs meet, mark that point as D.
• Join AD. Hence the required.
• ∴ AD ⊥ BC