Mathematics 4024 · O Level · Right-angled triangles
Right-angled triangles — practice question
ABCD is a field, and a straight path runs across it from B to D. Diagram details: DB = 495 m, DC = 620 m, BC = 580 m, angle ABD = 42^{\circ}, angle DAB = 90^{\circ}.
(a)[2]
Calculate the length of AB.
(b)[3]
Show that angle BDC = 61.5^{\circ}, correct to 1 decimal place.
(c)[5]
A second path goes across the field from C to meet path BD at point X. CX is the shortest distance from C to BD. Lara takes 6 minutes 24 seconds to walk along path CX. Calculate Lara’s average speed. Give your answer in kilometres per hour.
Worked solution & mark scheme
This 10-mark question has a full step-by-step worked solution and mark scheme. One marking point: “Therefore, \(\cos42=\frac{AB}{495}\)” …