CBSE Class 10 Mathematics Triangles MCQs Set D

Question. In the Fig., ΔODC ~ ΔOBA, ∠BOC = 125° and ∠CDO = 70°. Find ∠OAB.

(a) 55°
(b) 70°
(c) 125°
(d) 110°

Answer: A

Question. DE is drawn parallel to the base BC of a ΔABC, meeting AB at D and AC at E. If AB = 4 and CE = 2cm, find AE.
(a) 8cm
(b) 6cm
(c) 4cm
(d) 2cm

Answer: B

Question. In the given figure, P and Q are points on the sides AB and AC respectively of a ΔABC. PQ‖BC and divides the ΔABC into 2 parts, equal in area. The ratio of PA:PB =

(a) 1:1
(b) (√2 – 1):√2
(c) 1:√2
(d) 1: (√2 – 1)

Answer: D

Question. In the given fig. DE || BC, ∠ADE = 70° and ∠BAC = 50°, then angle ∠BCA =

(a) 50°
(b) 60°
(c) 70°
(d) 80°

Answer: B

Question. In the given figure, AD = 2cm, BD = 3 cm, AE = 3.5 cm and AC = 7 cm. Is DE parallel to BC?

(a) Yes
(b) No
(c) Neither Yes nor No
(d) None of these

Answer: B

Question. In the given figure, DE‖BC. The value of EC is

(a) 1.5cm
(b) 3cm
(c) 2cm
(d) 1cm

Answer: C

Question. It is given that ΔABC~ ΔDEF with BC/EF = 1/3. Then ar(Δ𝐷DF)/ar(ΔBCA) is equal to
(a) 9
(b) 3
(c) 1/3
(d) 1/9

Answer: A

Question. The areas of two similar triangles ABC and PQR are in the ratio 9:16. If BC = 4.5cm, then the length of QR is
(a) 4cm
(b) 4.5cm
(c) 3cm
(d) 6cm

Answer: D

Question. The areas of two similar triangles ABC and DEF are 36 cm2and 81 cm2 respectively. If EF = 6.75 cm, find BC.
(a) 6cm
(b) 9cm
(c) 5.5cm
(d) 4.5cm

Answer: D

Question. In the given figure, express x in terms of a, b and c

(a) 𝑥 = ab/𝑎+𝑏
(b) 𝑥 = ab/b+c
(c) 𝑥 = bc/b+c
(d) 𝑥 = ac/a+b

Answer: B

Question. In the Fig., if LM || CB and LN || CD, then

(a) AM/AB = AN/AD
(b) AM/AB = AN/ND
(c) AL/AC = AN/ND
(d) None of these.

Answer: A

Question. ΔABC is an equilateral triangle with each side of length 2p. If AD⊥BC. Then the value of AD is

(a) √3
(b) √3p
(c) 2p
(d) 4p

Answer: B

Question. If ΔABC ~ ΔAPQ and ar(ΔAPQ) = 4[ar(ΔABC)], then the ratio of BC to PQ is
(a) 2:1
(b) 1:2
(c) 1:4
(d) 4:1

Answer: B

Question. The length of the side of a square whose diagonal is 16cm, is
(a) 8√2cm
(b) 2√8cm
(c) 4√2 cm
(d) 2√2 cm.

Answer: A

Question. Two poles of height 6m and 11m stand vertically upright on a plane ground. If the distance between their foot is 12m, then distance between their tops is
(a) 12m
(b) 14m
(c) 13m
(d) 11m

Answer: C

Question. The areas of two similar triangles are 81cm2 and 49cm2 respectively, then the ratio of their corresponding medians is
(a) 7:9
(b) 9:8/1
(c) 9:7
(d) 81:7

Answer: C

Question. Sides of two similar triangles are in the ratio 4:9. Ares of these triangles are in the ratio
(a) 2:3
(b) 4:9
(c) 81:16
(d) 16:81

Answer: D

Question. A vertical pole of length 6 m casts a shadow 4 m long on the ground and at the same time a tower casts a shadow 28 m long. Find the height of the tower.
(a) 56m
(b) 24m
(c) 21m
(d) 42m

Answer: D

Question. O is the point of intersection of two equal chords AB and CD such that OB = OD, then triangles OAC and ODB are

(a) Equilateral but not similar
(b) Isosceles but not similar
(c) Equilateral and similar
(d) Isosceles and similar

Answer: D

Question. A 5m long ladder is placed leaning towards a vertical wall such that it reaches the wall at a point 4m high. If the foot of the ladder is moved 1.6m towards the wall, then the distance by which the top of the ladder would slide upwards on the wall is
(a) 0.6m
(b) 0.2m
(c) 0.4m
(d) 0.8m

Answer: D

Question. The lengths of the diagonals of a rhombus are 30cm and 40cm. The length of the side of the rhombus is
(a) 20cm
(b) 25cm
(c) 10cm
(d) 15cm

Answer: B

Question. The perimeter of two similar triangles ABC and LMN are 60cm and 48cm respectively. If LM = 8cm then the length of AB is
(a) 20cm
(b) 15cm
(c) 10cm
(d) 25cm

Answer: C

Question. In an equilateral triangle PQR if PS ┴ QR then PS2 = ______
(a) 5RS2
(b) 4RS2
(c) RS2
(d) 3RS2

Answer: D

Question. The length of the hypotenuse of an isosceles right triangle whose one side is 3√2 is
(a) 6cm
(b) 9cm
(c) 18cm
(d) 27cm

Answer: A

Question. A chord of a circle radius 5 cm subtends a right angle at the centre. The length of the chord is
(a) 10cm
(b) 5√2cm
(c) 15√2 cm
(d) 20cm

Answer: B