Geometry Questions

Multiple choice
  1. 15 cm./सेमी.

  2. 20 cm./सेमी.

  3. 24 cm./सेमी.

  4. 25 cm./सेमी.

Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

For two circles with radii 15 cm and 20 cm, and center distance 25 cm, note that 15² + 20² = 225 + 400 = 625 = 25², so the circles intersect at right angles. The common chord length is 2√(15² - d₁²), where d₁ = 15²/25 = 9. So chord length = 2√(225 - 81) = 2√144 = 2 × 12 = 24 cm.

Multiple choice
  1. 12 cm./सेमी.

  2. 13 cm./सेमी.

  3. 16 cm./सेमी.

  4. 17 cm./सेमी.

Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The perpendicular from the center to the chord bisects it and passes through the point of tangency. Using Pythagoras theorem: half the chord length = sqrt(radius of larger circle^2 - radius of smaller circle^2) = sqrt(100 - 36) = sqrt(64) = 8 cm. Therefore, the full chord length is 16 cm.

Multiple choice
  1. 8 π cm./सेमी.

  2. 12 π cm./सेमी.

  3. 16 π cm./सेमी.

  4. 7.4 π cm./सेमी.

Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

For sides 35, 44, 75: s = (35+44+75)/2 = 77. Area = sqrt(77*42*33*2) = sqrt(212052) ≈ 460.5 cm². Inradius r = Area/s = 460.5/77 ≈ 5.98. Circumference = 2πr = 2π*4 = 8π. Wait, let me recalculate: sqrt(77*42*33*2) = sqrt(212052) ≈ 460.5. But notice: 35+44 = 79, which is > 75, so triangle is valid. Actually, r = A/s. But let's use formula: r = (a+b-c)/2 for any triangle? No, that's for right triangles. For any triangle, r = A/s. Let me recalculate: 77*42*33*2 = 212052. sqrt(212052) = 460.5. r = 460.5/77 = 5.98. Circumference = 2π*5.98 ≈ 37.6 = 12π (since 12π ≈ 37.7). Option B (12π) is correct.

Multiple choice
  1. 13.6857

  2. 13.8675

  3. 31.6875

  4. 13.6875

Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

For radius 5, chord at 3 cm: half-chord = 4 cm (3-4-5 triangle). Original chord = 8 cm. Half chord = 4 cm. Distance from center: sqrt(5² - 4²) = 3 cm. This tests circle geometry: chord length and distance from center relationship.

Multiple choice
  1. 8 cm/ सेमी.

  2. 12 cm/ सेमी.

  3. 20 cm/ सेमी.

  4. 16 cm/ सेमी.

Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

OO' is the perpendicular bisector of common chord PQ. Triangle OMQ is right-angled at M. OQ = 17 cm (radius), OM = 15 cm (distance from center to chord). Using Pythagoras: PM² = OQ² - OM² = 17² - 15² = 289 - 225 = 64, so PM = 8 cm. Since M is midpoint of PQ, total PQ = 2 × PM = 16 cm.

Multiple choice
  1. 72o

  2. 108o

  3. 90o

  4. 36o

Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Given ∠NOQ = 108° and QM = QN, triangle NQM is isosceles at Q. In circle geometry, when a diameter (PQ) intersects a chord (MN) at O', if QM = QN, then O' is the midpoint of MN. Since PQ is a diameter passing through center O, and O' lies on MN, the line PO'N is perpendicular to MN. Therefore ∠PO'N = 90°.

Multiple choice
  1. 1:2

  2. 2:1

  3. 2:3

  4. 3:2

Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

For square with side 10 cm, circumscribed circle has diameter = diagonal = 10√2 cm, so radius = 5√2 cm. Area = π(5√2)² = 50π. Inscribed circle has diameter = side = 10 cm, so radius = 5 cm. Area = π(5)² = 25π. Ratio of areas = 50π : 25π = 2:1. The circumscribed circle always has twice the area of the inscribed circle for a square.

Multiple choice
  1. 4 cm./सेमी

  2. 5 cm./सेमी

  3. 6 cm./सेमी

  4. 8 cm./सेमी

Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

For two intersecting chords, the products of the segments are equal: AP × BP = CP × DP. Given AB = 13, so AP = 13 - BP. Also CD = 9 and PC = 6, so PD = 9 - 6 = 3. Then (13 - BP) × BP = 6 × 3 = 18. Solving BP² - 13BP + 18 = 0 gives BP = 4 or 9. Since AB = 13 and BP must be less than AB, BP = 4 cm.

Multiple choice
  1. 5.5

  2. 5

  3. 3.5

  4. 3

Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Radius r = 6.5m. Distance from center to chord with length L is d = √(r²-(L/2)²). For L=5: d₁ = √(42.25-6.25) = 6m. For L=12: d₂ = √(42.25-36) = 2.5m. Both chords same side, so gap = 6-2.5 = 3.5m. Option D (3) forgets 0.5, B (5) is miscalculation, A (5.5) adds instead of subtracts.

Multiple choice
  1. 5.6

  2. 7.3

  3. 8.0

  4. 9.0

Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The chord of the larger circle (radius 5 cm) touches the smaller circle (radius 3 cm) at one point. The perpendicular from the common center to the chord equals the smaller radius = 3 cm. This forms a right triangle with: half-chord (one leg), 3 cm (other leg), and 5 cm (hypotenuse). By Pythagoras: (half-chord)^2 + 3^2 = 5^2 → (half-chord)^2 = 25 - 9 = 16 → half-chord = 4 cm. Full chord length = 2 × 4 = 8 cm.

Multiple choice
  1. 36π

  2. 72π

  3. 144π

  4. 57π

Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

POQ is right-angled at O, with PO and OQ as radii (both equal to r). Area of ΔPOQ = (1/2) × PO × OQ = (1/2)r² = 72. Therefore r² = 144. Area of circle = πr² = 144π. Option C is correct.

Multiple choice
  1. 77o

  2. 80o

  3. 85o

  4. 90o

Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Using the intersecting chords theorem, the angle between two chords equals half the sum of the arcs they intercept. Given ∠POR = 100° is the central angle subtended by arc PR, and ∠SPA = 30° at the intersection point A, we can determine that ∠PAR = 80° by applying the vertical angles property and angle sum relationships in the quadrilateral formed by the intersecting chords.

Multiple choice
  1. 5 cm/सेमी.

  2. greater than 5 cm/5 सेमी. से बड़ी

  3. greater than or equal to 5 cm/5सेमी. के बराबर या इससे बड़ी

  4. less than 5 सेमी. से छोटी

Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The diameter is the longest chord of a circle, so any chord must be less than or equal to the diameter (2 × radius). If chord = 10.1 cm, then 2r ≥ 10.1, meaning r ≥ 5.05 cm. Thus, the radius must be strictly greater than 5 cm (not equal to 5).

Multiple choice
  1. 12π

  2. 128π

Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Using the tangent-radius theorem, the tangent is perpendicular to the radius at the point of contact, forming a right triangle. By Pythagoras theorem: radius = sqrt(10^2 - 8^2) = 6 cm. Perimeter = 2πr = 12π.

Multiple choice
  1. 600

  2. 900

  3. 300

  4. 1200

Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

PQ is a diameter, so ∠PRQ = 90° (angle in semicircle). Given ∠QPR = 30°, then ∠PQR = 60°. By alternate segment theorem, ∠PRS = ∠PQR = 60°. In cyclic quadrilateral PQRS, opposite angles sum to 180°, so ∠RQS = 180° - 60° = 120°.