Geometry Questions

Multiple choice
  1. 18.36 cm2

  2. 13.56 cm2

  3. 14.32 cm2

  4. 12.32 cm2

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

Area of sector = (θ/360) × πr². Given r = 5.6 cm, θ = 45°. Area = (45/360) × π × (5.6)² = (1/8) × π × 31.36 = 3.92π ≈ 3.92 × 3.14 ≈ 12.32 cm². Option D is correct.

Multiple choice
  1. 18.36 cm2

  2. 13.56 cm2

  3. 14.32 cm2

  4. 36.96 cm2

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

Area of sector = (θ/360°) × πr². With θ = 60°, r = 8.4 cm: Area = (60/360) × π × 8.4² = (1/6) × 3.14 × 70.56 = 36.96 cm². Option A (18.36) is exactly half - perhaps if θ was 30° instead of 60°.

Multiple choice
  1. 4π cm.2 / सेमी.2

  2. 6π cm.2 / सेमी.2

  3. 8π cm.2 / सेमी.2

  4. 2π cm.2 / सेमी.2

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

The 6-8-10 triangle is a right triangle (3-4-5 scaled by 2). Inradius r = Area/semiperimeter for any triangle. Area = (6×8)/2 = 24 cm², semiperimeter = 12 cm, so r = 24/12 = 2 cm. Area of incircle = πr² = π(2)² = 4π cm².

Multiple choice
  1. 3o

  2. 4o

  3. 5o

  4. 6o

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

For circle 1: arc length L1 = (30/360) × 2πr = πr/6. For circle 2: radius R=3r, let angle be θ. Given L1 = 2×L2, so πr/6 = 2 × (θ/360) × 2π(3r). Solving: πr/6 = 2 × (θ/360) × 6πr. Canceling πr: 1/6 = 12θ/360, so θ = 360/(72) = 5°. The key is relating arc lengths through radius and angle.

Multiple choice
  1. 11 cm / सेमी

  2. 5.5 cm / सेमी

  3. 16.5 cm / सेमी

  4. 22 cm / सेमी

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

Arc length formula: L = (θ/360) × 2πr, where θ = 90° and r = 3.5 cm. L = (90/360) × 2π × 3.5 = (1/4) × 7π = 1.75π ≈ 5.5 cm. The arc length is 5.5 cm.

Multiple choice
  1. 300

  2. 350

  3. 250

  4. 200

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

AB is diameter, so ∠ABO = 90° (angle in semicircle). In ΔAOB, ∠AOB = 115° (given as POB, same angle), so ∠OAB = 180° - 90° - 115° = 25°. PA is tangent, so ∠OAP = 90° (radius ⟂ tangent). In ΔOAP, ∠APO = 180° - 90° - 65° = 25°. The key is recognizing tangent-radius perpendicularity and angle in semicircle property.

Multiple choice
  1. 2 cm.

  2. 3 cm.

  3. 2.5 cm

  4. 1.8 cm.

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

Arc length of a sector = (θ/360) × 2πr, where θ is the central angle. Here arc length = (150/360) × 2π × 6 = 5π cm. When bent into a full circle, circumference = 2πR = 5π, giving R = 2.5 cm. Options A, B, and D are calculation errors.

Multiple choice
  1. 6 units/इकाई

  2. 9 units/इकाई

  3. 12 units/इकाई

  4. 15 units/इकाई

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

By tangent-secant theorem: PT² = PA × PB. Given 2PT = AP (so AP = 2PT) and AB = 18. Then PB = AP - AB = 2PT - 18. Substituting: PT² = 2PT(2PT - 18). PT² = 4PT² - 36PT. Therefore PT = 12 units.

Multiple choice
  1. 36 cm/सेमी

  2. 42 cm/सेमी

  3. 40 cm/सेमी

  4. 20 cm/सेमी

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

For a circle, chord length L at distance d from center with radius r is L = 2√(r² - d²). Here: 2√(29² - 21²) = 2√(841-441) = 2√400 = 2 × 20 = 40 cm.

Multiple choice
  1. 36 cm2/सेमी2

  2. 72 cm2/सेमी2

  3. 54 cm2/सेमी2

  4. 64 cm2/सेमी2

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

For a triangle with medians of lengths 9 cm, 12 cm, and 15 cm, these form a right triangle (9² + 12² = 81 + 144 = 225 = 15²). The area of a triangle with medians ma, mb, mc is (4/3) times the area of the triangle formed by the medians. Area of triangle with sides 9, 12, 15 = (1/2) * 9 * 12 = 54 cm². Therefore, area of original triangle = (4/3) * 54 = 72 cm². Option A (36 cm²) is incorrectly calculated without the 4/3 factor. Option C (54 cm²) is the area of the median triangle, not the original triangle. Option D (64 cm²) has no mathematical basis in this problem.

Multiple choice
  1. 9.6 cm/सेमी.

  2. 4.8 cm/सेमी.

  3. 1.4 cm/सेमी.

  4. 23.04 cm/सेमी.

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

दिए गए वृत्त में (त्रिज्या = 5 cm), AB = AC = 6 cm। PAB और PAC समद्विबाहु त्रिभुजे हैं। बिंदु P से AB और AC पर लंब D और E हैं। AD = sqrt(6^2 - 5^2) = sqrt(11)। बिंदु A से BC पर लंब की लंबाई = AE = sqrt(36 - 11) = 5 cm। BC = 2 × BD = 2 × sqrt(36 - 25) = 2 × sqrt(11) ≈ 9.6 cm।

Multiple choice
  1. 30o

  2. 60o

  3. 45o

  4. 90o

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

For two equal circles touching externally at C with common tangent AB, the radii to the point of tangency are perpendicular to the tangent. This creates two radii OA and OB perpendicular to AB. Since O, C, and the point of tangency are collinear, triangle AOB is a right triangle with OA and OB as perpendicular legs, making angle ACB = 90°. Option D is correct.

Multiple choice
  1. 18 cm

  2. 9 cm

  3. 12 cm

  4. 16 cm

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

For first chord (24 cm) in circle of radius 15 cm: half chord = 12 cm. Distance from center d₁ = √(15² - 12²) = √(225-144) = √81 = 9 cm. Distance between chords is 21 cm, so d₂ = |21 ± 9| = 12 cm or 30 cm. Since 30 > 15, d₂ = 12 cm. Half of other chord = √(15² - 12²) = √(225-144) = 9 cm. Full chord = 2 × 9 = 18 cm. Option A is correct.

Multiple choice
  1. 350

  2. 550

  3. 650

  4. 750

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

Given two circles touching externally at P, AB is direct common tangent. PA is tangent to circle A at A, so ∠PAB = 90° (tangent ⊥ radius). In triangle PAB: ∠PAB + ∠ABP + ∠BPA = 180°. If ∠PAB = 35° (likely 35°, not 350° which exceeds 180°), and since PB is also tangent, ∠PBA = 90°. However, with given ∠PAB = 35°, using angle sum: ∠ABP = 180° - 90° - 35° = 55°.

Multiple choice
  1. 289π

  2. 529π

  3. 441π

  4. 361π

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

For a chord at distance d from center, radius r = sqrt((L/2)² + d²). Here: r = sqrt(15² + 8²) = sqrt(225 + 64) = sqrt(289) = 17 cm. Area = πr² = π(289) = 289π. The perpendicular from center bisects the chord, forming a right triangle.