ADDITIONAL QUESTIONS AND ANSWERS
1) Find the number of right angles turned when
(a) The hour hand of a clock goes from 4 to 7.
Ans : 1 right angle.
(b) East and turn anti-clockwise to south.
Ans : 3 right angles.
(c) North and turn to south.
Ans : 2 right angles.
(d) The hour hand of a clock goes from 11 to 5.
Ans : 2 right angles.
(e) Starts at 9 and completes one revolution.
Ans : 4 right angles.
2) What are the degree measures of the following angles?
(a) Straight angle.
Ans : 180˚
(b) Complete angle.
Ans : 360˚
(c) Right angle.
Ans : 90˚
3) Write the angle name for
(a) Half a revolution.
Ans : Straight angle.
(b) One fourth revolution.
Ans : Right angle.
(c) Two one fourth revolution.
Ans : Straight angle.
(d) Less than complete but more than half a revolution.
Ans : Reflex angle.
4) If R,Q,P,S are four points on a line such that QR = 5 cm, RS = 5.5 cm, PQ = 4 cm, SP = 14.5 cm and PR = 9 cm.Which two points of them lies between the other two points.
Ans :
Hence point Q and point R his between point P and point S
5) Identify the type of angle from the following
Ans :
(a) Straight angle (b) Acute angle (c) Reflex angle (d) Right angle (e) Obtuse angle.
6) Find the measure of ∠ a in the following :
(1)
(2)
(3)
(4) 
Ans :
(1) ∠ a = 90˚− 30˚
(2) ∠ a = 180˚ − 115˚ = 65˚
(3) ∠a = 180˚− 162˚
(4) ∠a = 180˚ − (62˚ + 78˚)
= 180 – 140 = 40˚
7) Identify whether the following are polygons. If not state the reason.
Ans :
(a) Polygon .
(b) Not a polygon since it is not closed.
(c) Not a polygon since it is not made up of line segments.
(d) Polygon.
8) Find the measure of x, y, z in the following :
Ans :
(1) m ∠ x = 180 – 125 = 55˚
(2) m ∠ x + m ∠ y + 90˚ = 180˚
m ∠ y = 180 – (90 − ∠ x ) (angle sum property of triangle)
= 180 − (90 − 55) = 35˚
(3) m ∠z = 180˚ − (115˚ + y)
= 180˚ − (115˚ + 35˚)
= 180˚ − (150˚) = 30˚
9) Match the following :
| Column I | Column II |
| (1) Opposite sides parallel and equal | (a) Scalene |
| (2) Unequal sides of triangle | (b) Straight angle |
| (3) 8 sided polygon | (c) Square |
| (4) Two equal sides of triangle | (d) Rhombus |
| (5) Half a revolution | (e) Isosceles |
| (6) 4 right angles | (f) Parallelogram |
| (g) Octagon |
10) State whether true or false :
(1) A cuboid has six faces.
(2) Isosceles triangle has 3 equal sides.
(3) The sum of the measure of all angles of a triangle is 180˚.
(4) A polygon is regular if it’s all sides are equal .
(5) An equilateral triangle is also considered as an isosceles triangle.
(6) The measure of each angle is 90˚in an equilateral triangle.
Ans : (1) True (2)False (3) True (4) False (5) False (6) False