## Construction of Triangles and Circles Exercise

1. Make the following constructions:

(a) A circle with a radius of 4.5 cm.
Use your ruler to measure its diameter.
(b) Construct an equilateral triangle with all sides of length 5 cm, using ruler and compasses.
Use your protractor to measure the size of one of the angles.
(c) A right angled triangle with the two shortest sides of 3 centimetres and 4 centimetres.
Use your ruler to measure the length of the longest side.

2. Draw three different sized triangles

a. Measure the lengths of the two shorter sides of each triangle and add them together.
b. Measure the length of the longest side.
c. Is the length of the longest side ever greater than the sum of the two shorter sides?

3. Make the following constructions:

a. Construct an isosceles triangle with two sides of 6 cm.
b. Construct any triangle with two sides of 4.5 cm
c. Construct a triangle with two angles of 55o.

4. Make the following constructions:

(a) Mark three points on your paper.
(b) Label them A, B and C.
(c) Join them to form a triangle ABC.
(d) Use your ruler to measure the lengths of sides AB, BC and AC.
(Measure to the nearest millimetre).
(e) Use your protractor to find the size of the three inside angles of the triangle (to the nearest degree).

5. Use a ruler, compasses and protractors to construct the following:

 a b c   6. Make the following constructions:

(a) Using a protractor or set square, construct an angle ABC of 60°.
(b) Use your ruler to make AB = 6 cm and BC = 6 cm.
(c) Join A and C to form triangle ABC.
(d) Measure the length of AC to the nearest millimetre.
(e) What kind of triangle is triangle ABC?

7. Using a ruler and compasses only, construct a triangle with sides of length 6.5 cm, 4.5 cm and 5.5 cm. Use your protractor to measure the sizes of each angle in the triangle (to the nearest degree).

8. Using a protractor, ruler and compasses draw a triangle PQR where PQ = 7 cm, angle PQR = 56° and the length of QR = 6 cm. Use your ruler to measure the length of side PR (to the nearest millimetre).

9. Using a ruler and a protractor draw a triangle ABC where AB = 5.6 cm, angle A = 61° and angle B =67°.

a. Measure the size of angle C.

b.Measure the lengths of sides BC and AC.

10. Use your compasses to draw three circles with the same centre and radii of 3 cm, 4cm and 6 cm. Shade the part of the circles that is between 3 cm and 4 cm from centre of the circles.