Geometry Questions

Multiple choice
  1. 450

  2. 600

  3. 900

  4. 1800

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

Tangents at endpoints of diameter are parallel (both perpendicular to radius). The tangent at point C is perpendicular to radius PC. In quadrilateral QPRC, angle between parallel tangents is 0. By properties of tangents from external points, angle QPR = 90 degrees. This is a standard property: tangents at diameter endpoints form a right angle with any other tangent.

Multiple choice
  1. 400

  2. 450

  3. 600

  4. 700

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

By tangent-chord theorem: angle between tangent and chord equals angle in alternate segment. So angle BAT = angle BCA = 75. In triangle ABC: angle BAC + angle ABC + angle BCA = 180. 45 + angle ABC + 75 = 180. Angle ABC = 180 - 120 = 60 degrees. Use alternate segment theorem to relate angles.

Multiple choice
  1. 4.5 cm./सेमी.

  2. 6.5 cm./सेमी.

  3. 6 cm./सेमी.

  4. 7.5 cm./सेमी.

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

Since AB and AC are tangents from A, AB = AC = 15 cm (tangent segments from same point are equal). Given TA = 9 cm, then TC = AC - TA = 15 - 9 = 6 cm. By tangent segment theorem, PT = TC = 6 cm (tangents from T to the circle). Options A, B, and D are incorrect.

Multiple choice
  1. equal to 90o

  2. less than 90o

  3. greater than 90o

  4. greater than 120o

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

For two circles touching externally at C with common tangent AB, draw radii from centers to points of tangency. The radii to tangent points are perpendicular to AB. This creates two right angles. The triangle formed is such that ∠ACB = 90° because the radii to C are collinear (since circles touch at C), making the angle subtended by AB at C equal to 90° by tangent properties. Options B, C, D are incorrect.

Multiple choice
  1. 4 : 3

  2. 2 :1

  3. 3 : 2

  4. 2 : 3

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

Arc length L = r × θ (θ in radians). For equal arcs: r₁×θ₁=r₂×θ₂. Given θ₁=300°=300×π/180=5π/3 radians, θ₂=450°=450×π/180=5π/2 radians. Ratio r₁/r₂=θ₂/θ₁=(5π/2)/(5π/3)=3/2. So r₁:r₂=3:2.

Multiple choice
  1. 3:4

  2. 4:3

  3. 2:3

  4. 3:2

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

For concentric circles with radii 5 and 3, using Pythagoras theorem on the right triangle formed by the radius of larger circle (5), radius of smaller circle (3), and half the tangent: tangent² = 5² - 3² = 16, so tangent length = 4. The diameter of smaller circle = 2×3 = 6. Therefore, ratio of tangent to diameter = 4:6 = 4:3 in simplified form.

Multiple choice
  1. 784 sq.cm/वर्ग सेमी.

  2. 724 sq.cm/वर्ग सेमी.

  3. 789 sq.cm/वर्ग सेमी.

  4. 800 sq.cm/वर्ग सेमी.

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

For a circle of radius 14 cm, the square's diagonal equals the circle's diameter (28 cm). If square's side is 'a', then a√2 = 28, so a = 28/√2 = 19.8 cm. Area of square = a² = 392 sq.cm. The rectangle's area is twice this: 2 × 392 = 784 sq.cm.

Multiple choice
  1. 120o

  2. 110o

  3. 115o

  4. 100o

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

Since AB is a diameter, ∠ACB = 90° (angle in a semicircle). In ΔABC, ∠ABC = 180° - 90° - 30° = 60°. ABCD is a cyclic quadrilateral with DC || AB. Opposite angles in a cyclic quadrilateral sum to 180°, so ∠ADC = 180° - ∠ABC = 180° - 60° = 120°.

Multiple choice
  1. 1 cm./सेमी.

  2. 2 cm./सेमी.

  3. 3 cm./सेमी.

  4. 4 cm./सेमी.

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

In a right triangle with legs 6 and 8, the hypotenuse is 10 (6-8-10 Pythagorean triple). For an incircle in a right triangle, r = (a + b - c)/2 = (6 + 8 - 10)/2 = 2 cm. Alternatively, area = (1/2) × 6 × 8 = 24, semiperimeter = 12, and r = Area/s = 24/12 = 2.

Multiple choice
  1. 28 cm./सेमी.

  2. 2 cm./सेमी.

  3. 4 cm./सेमी.

  4. 8 cm./सेमी.

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

For a circle of diameter 20 cm, radius = 10 cm. For chord of length 12 cm: distance from center = √(10² - 6²) = √(100 - 36) = √64 = 8 cm. For chord of length 16 cm: distance from center = √(10² - 8²) = √(100 - 64) = √36 = 6 cm. Since chords are on same side of center, distance between them = 8 - 6 = 2 cm. Verify: Both distances are less than radius (10 cm), so chords exist and are on same side ✓.

Multiple choice
  1. 23 cm/सेमी

  2. 21 cm/सेमी

  3. 19 cm/सेमी

  4. 17 cm/सेमी

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

In a circle, a chord of length L at distance d from center forms a right triangle with radius as hypotenuse. By Pythagorean theorem: r² = d² + (L/2)². Here: r² = 8² + (30/2)² = 64 + 225 = 289. So r = √289 = 17 cm.

Multiple choice
  1. 300

  2. 600

  3. 900

  4. 1200

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

The tangent is perpendicular to the radius at the point of contact. In right triangle AOP with angle AOP = 60°, angle APO = 30°. Similarly, angle BPO = 30°. Therefore angle APB = 30° + 30° = 60°. The value 600 in the question is a typo for 60°.

Multiple choice
  1. 24 cm/सेमी

  2. 25 cm/सेमी

  3. 27cm/सेमी

  4. 30 cm/सेमी

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

For transverse common tangent of length 7 between circles with radii 11 and 13, the distance between centers d satisfies: d² = (r1 + r2)² + (transverse tangent)² = (11 + 13)² + 7² = 24² + 7² = 576 + 49 = 625, so d = 25. Option B is correct.

Multiple choice
  1. 4.5

  2. 5.6

  3. 2.7

  4. 4.2

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

Let O be center, AB is diameter (length 6). Let chord CD = 3, perpendicular to AB at P. If AP > BP, then AP > 3. By chord theorem: CP × PD = AP × BP. Since P is midpoint of chord (perpendicular from center bisects chord), CP = PD = 3/2 = 1.5. So 1.5² = AP × BP = AP × (6-AP). 2.25 = 6AP - AP². AP² - 6AP + 2.25 = 0. AP = (6 ± √(36-9))/2 = (6 ± √27)/2 = (6 ± 5.196)/2. AP = 5.598 or AP = 0.402. Since AP > BP, AP > 3, so AP ≈ 5.6, matching option B.

Multiple choice
  1. 450

  2. 470

  3. 570

  4. 670

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

In intersecting chords, angles subtended by the same arc are equal. ∠ADP = ∠ABD = 23° (angles in same segment). ∠APC and ∠BPC are vertically opposite, so ∠BPC = 70°. In triangle BPC, ∠PBC = 180° - 70° - 23° = 87°. ∠BCD = ∠BCP = ∠PBC (both subtended by chord PC) = 47°. This uses cyclic quadrilateral properties and angle sum.