Worksheet on Understanding Elementary Shape for Class 6

Solved Questions on Understanding Elementary Shape

1. In the given figure, AOB is a straight line. If ?AOD = 69° and ?BOC = 47°,   what is the value of ?COD?

a) 44°
b) 54°
c) 64°
d) 74°

Answer: c) 64°

Explanation: ?AOD + ?COD + ?BOC = 180° [Supplementary angles]
? 69° + ?COD + 47° = 180°
? ?COD + 116° = 180°
? ?COD = 180° ? 116°
? ?COD = 64°

2. The sum of all the interior angles of a polygon is 2340°. How many sides does the polygon have?

a) 9
b) 11
c) 13
d) 15

Answer: d) 15

Explanation: Sum of interior angles in a polygon = 2340°

? (n ? 2) × 180° = 2340°
? (n ? 2) = 2340°/180°
? n ? 2 = 13
? n = 13 + 2
? n = 15

3. In the given figure, AOC is a straight line. If ?AOE = 90°, ?AOB = 52° and ?COD = 27°. What is the measure of ?EOD?

a) 33°
b) 43°
c) 53°
d) 63°

Answer: d) 63°

Explanation: ?AOE + ?COE = 180° [AOC is a straight line, Linear Pair]

? 90° + ?COE = 180°
? ?COE = 180° ?  90°
? ?COE = 90°
?EOD + ?COD = ?COE (Complementary Angles)
? ?EOD + 27° = 90°
? ?EOD = 90° – 27°
? ?EOD = 63°

4. What is the value of 1.5y?

a) 35°
b) 55°
c) 55°/3
d) 110°/3

Answer: b) 55°

Explanation: Figure shows the complete angle which is 360°.

? y + 75° + 2y + 65° + 3y = 360°
? 6y + 140° = 360°
? 6y = 360° ? 140°
? 6y = 220°
? y = 220°/6
? y =  110°/3

The value of 1.5y is:

? 1.5y =  1.5 × 110°/3 = 55°

5. For an angle z°, What is the value of z°/2 if its supplement is three times its complement?

a) 15 ½°
b) 22 ½°
c) 37 ½°
d) 45°

Answer: b) 22 ½°

Explanation: Supplement of an angle z° is three times its complement.

? Supplement of an angle z° = 3 × Complement of an angle z°
? 180° ? z° = 3 × (90° ? z°)
? 180° ? z° = 270° ? 3z°
? 3z° ? z° = 270° ? 180°
? 2z° = 90°
? z° = 90°/2
? z° = 45°

The value of z°/2  = 45°/2 = 22 ½°