In ΔABC, right-angled at B, AB = 24 cm, BC = 7 cm. Determine: (i) Sin A, cos A (ii) sin C, cos C
In right ΔABC, we have: perpendicular = 24 cm, base = 7 cm Using the Pythagoras' theorem, AC*AC = AB*AB + BC*BC AC*AC = 24*24 + 7*7 = 576 + 49 = 625 = 25*25 Hence, AC = 25. Sin A = BC/AC = 7/25 Cos A = AB/AC = 24/25 Sin C = AB/AC = 24/25 Cos C = BC/AC = 7/25
If the perimeter of a rectangle is 390 cm and the length is 30 cm, find the breadth and the area of the rectangle.
Given, P = 390 cm, L = 30 cm, B = ?, Area = ? P = 2(L+B) 390 = 2(30 + B) 390/2 = 30+B 195 = 30+B B = 165 cm Area = L X B Area = 30 X 165 Area = 4950 sq. cm.
If A covers 5 km in 20 min then how much it will cover in 50 min
Given A covers 5 km in 20 mins Speed of A = Distance/ Time Taken = 5 km/ 20 min = 0.25 km/min Hence, Distance covered in 50 min = 50 x 0.25 = 12.5 km