In second quadrant, cos is negative. Using sin²θ + cos²θ = 1: cos²θ = 1 - 9/25 = 16/25, so cos θ = -4/5

The sum of interior angles in any polygon depends only on the number of sides, following a fixed mathematical relationship.

For any polygon with n sides, the sum of all interior angles is given by the formula:

Since the polygon has 8 sides, substitute n = 8 into the formula:

The sum of angles in a polygon with 8 sides is 1080°.

Answer: (A) 1080°

log₂ x = 5 means 2⁵ = x, therefore x = 32

36 = 2²×3², 48 = 2⁴×3. HCF = 2²×3 = 12

a² + b² = (a+b)² - 2ab = 100 - 42 = 58

f'(x) = d/dx(3x² + 2x + 1) = 6x + 2

By Vieta's formulas, sum of roots = -b/a

Using Pythagoras theorem: distance = √(3² + 4²) = √(9 + 16) = √25 = 5 km

Perimeter = 2(l+b), 28 = 2(8+b), 14 = 8+b, b = 6 cm

Adding both equations: 5x + 5y = 25, so x + y = 5