Dark mode

Mathematical Methods — Question 8

QCAA 2020, Paper 2 · 1 mark

Q8 · 2020 · Technology-activeSimple familiar1 mark

QUESTION 8

Determine the size of angle

A

in the triangle.

Triangle ABC with AC=9.9, BC=8.8 and AB=11.3.

(A)

48.5^\circ

(B)

61.4^\circ

(C)

118.6^\circ

(D)

131.5^\circ

ABCD

Question linkOriginal paper

WORKED SOLUTION

Answer A

1 mark

ANSWER

A

Worked solution

Using the cosine rule,

\cos A=(9.9^2+11.3^2-8.8^2)/(2\cdot9.9\cdot11.3)

, giving

A\approx48.5^\circ

. Hence A.

Selects option A.

[1 mark]

Worked explanation by QCE Vault; correct option verified against the QCAA answer key.

View the full QCAA marking guide

Related questions

Q1 · 2025 QCAA · Paper 1 · 1 mark
Determine the value of $\displaystyle\int_1^2 3x^2\,dx$ .
Question and worked solution
Q2 · 2025 QCAA · Paper 1 · 1 mark
State the domain of the function $y=\ln(x)$ .
Question and worked solution
Q3 · 2025 QCAA · Paper 1 · 1 mark
A council wants to survey residents about a new dog park. Which sampling method would best minimise bias in the survey?
Question and worked solution
Q4 · 2025 QCAA · Paper 1 · 1 mark
Solve for $x$ in the equation $\ln(x)+\ln(2)=\ln(8)$ .
Question and worked solution