Sec 2 G2 Maths Trigonometric ratios worksheet with answers
A free Sec 2 G2 Maths worksheet on trigonometric ratios: 8 questions, 30 marks, short questions first and then structured ones, in the school exam style. The answers and full worked solutions are on the last page.
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Answer all questions. Show all your working. Give non-exact answers correct to 3 significant figures, or 1 decimal place for angles in degrees, unless the question says otherwise.
Section A
1
In the diagram, ∠ABC=90∘. Find x, correct to 3 significant figures.
Answercm[2]
2
A ramp 4 m long rises to a platform 1 m above level ground. Find the angle the ramp makes with the ground, x∘, correct to 1 decimal place.
Answer°[2]
3
In the diagram, ∠STU=90∘. Find x, correct to 1 decimal place.
Answer°[2]
4
The diagram shows the side view of a footbridge. The deck AB is 18 m long and C is the point on AB such that AC:CB=2:3. Two steel struts, AD and BD, support the deck; D is vertically below C and ∠BAD=30∘. Steel strut costs $85 per metre when the total length bought is 25 m or less, and $72 per metre for the whole order when more than 25 m is bought. Find the cost of the steel for the two struts, correct to the nearest $100.
Answer$[3]
5
In the diagram, ∠PQR=90∘, PR=52 cm and QR=48 cm. Find the value of tan∠RPQ, giving your answer as a fraction in its simplest form.
Answer[3]
Section B
6
(a)In the diagram, ∠STU=90∘, ST=10 cm and TU=24 cm. Write down the value of tan∠SUT, giving your answer as a fraction in its simplest form.
Answer (a)[2]
(b)In the diagram, ∠XYZ=90∘. Find x, correct to 3 significant figures.
Answer (b)cm[2]
7
(a)In the diagram, ∠KLM=90∘. Find x, correct to 3 significant figures.
Answer (a)m[2]
(b)A ramp 5 m long rises to a platform 1.2 m above level ground. Find the angle the ramp makes with the ground, x∘, correct to 1 decimal place.
Answer (b)°[2]
(c)In the diagram, ∠EFG=90∘, EG=34 cm and sin∠FEG=1715. The point H lies on FG such that FH:HG=3:1. Find the length of EH, correct to 3 significant figures.
Answer (c)cm[3]
8
(a)In the diagram, ∠LMN=90∘. Find x, correct to 3 significant figures.
Answer (a)cm[2]
(b)In the diagram, ∠WXY=90∘, XY=12 cm and sin∠XWY=54. The point Z lies on WY such that WZ:ZY=1:2. Find the length of WZ.
Answer (b)cm[2]
(c)From a point P on level ground in front of a block of flats, the angles of elevation of the top and the bottom of a window in the wall are 44∘ and 38∘. The bottom of the window is 10 m above the ground. Find the height of the window, h m, correct to 3 significant figures.
Answer (c)m[3]
END OF PAPER
Answers and worked solutions
Question 1
Answer: =2.72 cm (3 s.f.)[2]
From the 63° angle: the side x cm is the adjacent and the side 6 cm is the hypotenuse.cos63∘=6xx=6cos63∘=2.7239…=2.72 cm (3 s.f.)
Question 2
Answer: =14.5∘ (1 d.p.) °[2]
From the angle at the bottom of the ramp: the height 1 m is the opposite and the ramp, 4 m, is the hypotenuse.sinx∘=41x=sin−1(41)=14.4775…=14.5∘ (1 d.p.)
Question 3
Answer: =28.1∘ (1 d.p.) °[2]
From the angle x°: the side 8 cm is the opposite and the side 15 cm is the adjacent.tanx∘=158x=tan−1(158)=28.0724…=28.1∘ (1 d.p.)
Question 4
Answer: Cost=1690.3291…, so about $1700 (to the nearest $100).[3]
AC=52×18AC=7.2 m, so CB=18−7.2CB=10.8 mAD=cos30∘7.2AD=8.3138… mCD=7.2tan30∘CD=4.1569… mBD=10.82+(4.1569…)2BD=11.5723… mTotal=8.3138…+11.5723…Total=19.8862… m, which is not more than 25 m, so the price is $85 per metre.Cost=19.8862…×85Cost=1690.3291…, so about $1700 (to the nearest $100).
Question 5
Answer: =512[3]
PQ2=522−482=400PQ=400PQ=20 cmFrom ∠RPQ: QR is the opposite and PQ is the adjacent.tan∠RPQ=2048=512
Question 6
(a)Answer: =125[2]
From ∠SUT: ST is the opposite and TU is the adjacent.tan∠SUT=2410=125
(b)Answer: =11.8 cm (3 s.f.)[2]
From the 46° angle: the side x cm is the hypotenuse and the side 8.5 cm is the opposite.sin46∘=x8.5x=sin46∘8.5=11.8163…=11.8 cm (3 s.f.)
Question 7
(a)Answer: =16.4 m (3 s.f.)[2]
From the 35° angle: the side x m is the adjacent and the side 20 m is the hypotenuse.cos35∘=20xx=20cos35∘=16.3830…=16.4 m (3 s.f.)
(b)Answer: =13.9∘ (1 d.p.) °[2]
From the angle at the bottom of the ramp: the height 1.2 m is the opposite and the ramp, 5 m, is the hypotenuse.sinx∘=51.2x=sin−1(51.2)=13.8865…=13.9∘ (1 d.p.)
(c)Answer: =27.6 cm (3 s.f.)[3]
EGFG=1715 (from the sin ratio)FG=1715×34=30 cmFH=43×30=22.5 cmEH2=162+22.52EH2=762.25=27.6088…=27.6 cm (3 s.f.)
Question 8
(a)Answer: =3.61 cm (3 s.f.)[2]
From the 67° angle: the side x cm is the adjacent and the side 8.5 cm is the opposite.tan67∘=x8.5x=tan67∘8.5=3.6080…=3.61 cm (3 s.f.)
(b)Answer: =5 cm[2]
XYWY=45 (from the sin ratio, turned upside down)WY=45×12=15 cmWZ=31×15=5 cm
(c)Answer: =2.36 m (3 s.f.)[3]
tan38∘=d10, so d=tan38∘10d=12.7994… mTop: tan44∘=12.7994…T, so T=12.7994…tan44∘T=12.3602… mh=12.3602…−10=2.3602…=2.36 m (3 s.f.)