Class 8 Maths


Quadrilaterals

Extra Questions

Part 2

Question 6: Find the angle x

Triangle

Answer: We know that, angle sum of a triangle = 180⁰
So, `35° + x + x = 180°`
Or, `35° + 2x = 180°`
Or, `2x = 180° - 35° = 145°`
Or, `x = 145°÷2 = 72.5°`

Question 7: Find the angle x

Triangle

Answer: We know that, angle sum of a triangle = 180⁰
So, `30° + x + x = 180°`
Or, `30° + 2x = 180°`
Or, `2x = 180° - 30 ° = 150°`
Or, `x = 150°÷2 = 75°`

Question 8: Find the angle y

Triangle

Answer: We know that, angle sum of a triangle = 180⁰
So, `27° + x + x = 180°`
Or, `27° + 2x = 180°`
Or, `2x = 180° - 27° = 153°`
Or, `x = 153°÷2 = 76.5°`

Question 9: Find the angle y

Triangle

Answer: We know that, angle sum of a triangle = 180⁰
So, `90° + y + y = 180°`
Or, `90° + 2y = 180°`
Or, `2y = 180° = 90°`
Or, `y = 90°÷2 = 45°`

Question 10: Find the angle y

Triangle

Answer: We know that, angle sum of a triangle = 180⁰
So, `y + y + y = 180°`
Or, `3y = 180°`
Or, `y = 180°÷3 = 60°`