Draw five triangles and measure their sides. Check in each case, if the sum of the lengths of any two sides is always less than the third side.

5

(a)

Which direction will you face, if you start facing
(a) East and makes \(\frac { 1 }{ 2 } \) of a revolution, clockwise?
(b) East and make 1\(\frac { 1 }{ 2 } \) of a revolution, clockwise?
(c) West and makes \(\frac { 3 }{ 4 } \) of a revolution, anti-clockwise?
(d) South and makes one full revolution? (Should we specify clockwise or anti-clockwise for this last question? Why not?)

5

(a)

Name each polygon. Make two more examples of each of these.

5

(a)

Name the type of triangle and also draw it rough sketch.
(a) ΔABC ; \(\angle A = \angle B = \angle C = 60°\)
(b) ΔABC; \(\angle B = \angle C = 50°\)
(c) ΔABC ; \(\angle A = 45°, \angle B = 45°, \angle C = 90°\)
(d) ΔABC; \(\angle A = 50°, \angle B = 60°, \angle C = 70°.\)

5

(a)

In figure, BCDE is a square and a 3-D shape has been formed by joining the point A in space with the vertices B, C, D and E. Name the 3-D shape and also its
(i) vertices
(ii) edges and
(iii) faces.

5

(a)

Name the following angles of figure using three alphabets.
(a) \(\angle 1\)
(b) \(\angle 2\)
(c) \(\angle 3\)
(d) \(\angle 1 + \angle 2\)
(e) \(\angle 2 + \angle 3\)
(f) \(\angle 1+\angle 2+\angle 3\)
(g) \(\angle CBA-\angle 1\)

5

(a)

If in ΔABC, \(\angle A = \angle B = \angle C\) and AB = 4 cm. Then find measure of other two sides.

5

(a)

If line segment AB = 10 cm and C, D, E, F are four points at line segment AB, such that AC = CD = DE = EF = FB. Then, find measure of AD.

5

(a)

Find \(\angle ABC\), if \(\angle ABD = 70°, \angle DBC = 45°\) (as shown in figure).

5

(a)

Using four unequal sticks, as you did in the above activity, see if you canform a quadrilateral such that 
(a) all the four angles are acute.
(b) one of the angles is obtuse.
(c) one of the angles is right-angled.
(d) two of the angles are obtuse.
(e) two of the angles are right-angled.
(f) the diagonals are perpendicular to one another.

5

(a)