Home / iGCSE Mathematics (0580) :E6.5 Solve simple trigonometrical problems in three dimensions including angle between a line and a plane.iGCSE Style Questions Paper 2

iGCSE Mathematics (0580) :E6.5 Solve simple trigonometrical problems in three dimensions including angle between a line and a plane.iGCSE Style Questions Paper 2

Question

Calculate the shortest distance from C to AB.

▶️ Answer/Explanation
Solution

Ans: 9.40 cm

Shortest distance is perpendicular from C to AB.

Using right triangle trigonometry: distance = BC × sin(33.14°).

Calculation: 17.2 × sin(33.14°) ≈ 9.40 cm.

Question

Calculate the area of triangle ABC.

▶️ Answer/Explanation
Solution

Ans: 5.36 cm² (5.360 to 5.361)

Given the triangle ABC with sides \(a = 4.9 \, \text{cm}\), \(b = 5.6 \, \text{cm}\), and included angle \(C = 23^\circ\), the area is calculated using the formula:

\[ \text{Area} = \frac{1}{2}ab \sin C \]

Substitute the known values:

\[ \text{Area} = \frac{1}{2} \times 4.9 \times 5.6 \times \sin(23^\circ) \]

First, compute \(\sin(23^\circ) \approx 0.3907\).

Now, multiply the values:

\[ \text{Area} = \frac{1}{2} \times 4.9 \times 5.6 \times 0.3907 \approx \frac{1}{2} \times 10.717 \approx 5.36 \, \text{cm}^2 \]

Thus, the area of triangle ABC is approximately 5.36 cm².

Scroll to Top