Question 3 - Figure it out - Page 169-170 - Chapter 7 Class 8 - Area (Ganita Prakash II)

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Question 3 (i) Find the areas of the following figures:Rotating it, we notice that this is a Trapezium with Parallel sides 10 ft and 7 ft, i..e a = 10 ft & b = 7ft And, height 16 ft h = 16 ft Now, Area of Trapezium = 1/2 × (Sum of Parallel Sides) × Height = 1/2 × (a + b) × h = 𝟏/𝟐 × (10 + 7) × 16 = 1/2 × 17 × 16 = 17 × 8 = 136 ft2 Question 3 (ii) Find the areas of the following figures:This is a Trapezium with Parallel sides 36 m and 24 m, i..e a = 36 m & b = 24 m And, height 14 m h = 14 m Now, Area of Trapezium = 1/2 × (Sum of Parallel Sides) × Height = 1/2 × (a + b) × h = 𝟏/𝟐 × (36 + 24) × 14 = 1/2 × 60 × 14 = 30 × 14 = 420 m2 Question 3 (iii) Find the areas of the following figures:Rotating it, we notice that this is a Trapezium with Parallel sides 14 in and 6 in, i..e a = 14 in & b = 6 in And, height 10 in h = 10 in Now, Area of Trapezium = 1/2 × (Sum of Parallel Sides) × Height = 1/2 × (a + b) × h = 𝟏/𝟐 × (14 + 6) × 10 = 1/2 × 20 × 10 = 10 × 10 = 100 in2 Question 3 (iv) Find the areas of the following figures:We notice that this is a Trapezium with Parallel sides 18 ft and 12 ft, i..e a = 18 ft & b = 12 ft And, height 8 ft h = 8 ft Now, Area of Trapezium = 1/2 × (Sum of Parallel Sides) × Height = 1/2 × (a + b) × h = 𝟏/𝟐 × (18 + 12) × 8 = 1/2 × 30 × 8 = 30 × 4 = 120 ft2