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