Geometry Questions

Multiple choice
  1. 60o

  2. 120o

  3. 150o

  4. 135o

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

When chord = radius r, the triangle formed by two radii and the chord is equilateral (all sides = r). Central angle = 60°. The angle subtended at the minor arc = 180° - 60° = 150° (opposite angles of cyclic quadrilateral sum to 180°).

Multiple choice
  1. 48o

  2. 36o

  3. 96o

  4. 120o

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

By the alternate segment theorem, ∠ABC = ∠ACT = 48°. In triangle ABC, ∠BAC = 180° - ∠ATC - ∠ACT = 180° - 36° - 48° = 96°. The angle subtended by chord AB at the center is twice the angle subtended at any point on the circumference, so central angle = 2 × ∠ACB. ∠ACB = 180° - 96° - 48° = 36°. Central angle = 2 × 48° = 96°.

Multiple choice
  1. 75o

  2. 70o

  3. 65o

  4. 80o

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

D is the midpoint of chord AB, so OD is perpendicular to AB (property: line from center to midpoint of chord is perpendicular to chord). Similarly, OE is perpendicular to AC. This means ∠BAC = 40° is an inscribed angle subtending arc BC. Central angle ∠BOC = 2 × ∠BAC = 80°. Points F and G are on the circle, and H is on the major arc FG. Using cyclic quadrilateral properties, ∠FHG = (180° - ∠FOG)/2. After calculation: ∠FHG = 180° - ∠F O G/2 = 180° - 40° = 140°, then using chord properties: ∠FHG = 70°.

Multiple choice
  1. 3cm

  2. 2.5cm

  3. 2cm

  4. 1cm

  5. None of these

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

Triangle with sides 6, 8 is a 3-4-5 triangle scaled by factor 2. Hypotenuse = 10cm. For a right triangle, inradius r = (a + b - c)/2 where c is hypotenuse. So r = (6 + 8 - 10)/2 = 4/2 = 2cm. Alternatively, area = 24 = r × s where s = semiperimeter = 12, giving r = 2. Options A and D overestimate the inradius.

Multiple choice
  1. 7 cm / सेमी

  2. 5 cm / सेमी

  3. 4 cm / सेमी

  4. 6 cm / सेमी

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

In the circle, OM is perpendicular to chord AB. M is midpoint of AB, so AM = MB = 4 cm. Let OM = d. In right triangle OMA: OA² = OM² + AM² = d² + 16 = r². Given MP = 2 cm. Since OM + MP = OP = r (if P lies on radius extended), we have d + 2 = r. Substituting: r² = (r-2)² + 16 = r² - 4r + 4 + 16, giving 4r = 20, so r = 5 cm.

Multiple choice
  1. 60o

  2. 30o

  3. 45o

  4. 90o

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

Let M be the midpoint of chord AB. In right triangle OMA: OM = r/2 (given, half the radius), OA = r (radius). Using trigonometry: cos(∠AOM) = OM/OA = (r/2)/r = 1/2, so ∠AOM = 60°. Since OM is perpendicular to AB, ∠BAO = 90° - 60° = 30°. This uses the property that the line from the center to a chord's midpoint is perpendicular to the chord.

Multiple choice
  1. 3.7 cm./सेमी.

  2. 0.8 cm./सेमी.

  3. 1.2 cm./सेमी.

  4. 1.0 cm./सेमी.

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

By the Angle Bisector Theorem, in triangle ABC with angle bisector AD, we have: BD/DC = AB/AC. Given AB = 2.8 cm, AC = 4.9 cm, and DC = 2.1 cm. So BD/2.1 = 2.8/4.9, which gives BD/2.1 = 4/7, therefore BD = 2.1 x 4/7 = 1.2 cm.

Multiple choice
  1. 55o

  2. 45o

  3. 75o

  4. 90o

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

For intersecting chords in a circle, the angle formed at the intersection point equals half the sum of the measures of the arcs intercepted by the angle and its vertical angle. Here, ∠QTS = 1/2(arc(QS) + arc(PR)). Given ∠QOS = 50° and ∠POR = 60°, the sum of these central angles is 110°, and ∠QTS = 110°/2 = 55°.

Multiple choice
  1. 14 cm

  2. 15 cm

  3. 16 cm

  4. 17 cm

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

For chord AB = 10 cm in a circle of radius 13 cm: distance from center d1 = √(13² - 5²) = √(169 - 25) = √144 = 12 cm. For chord CD = 24 cm: distance from center d2 = √(13² - 12²) = √(169 - 144) = √25 = 5 cm. Since chords are on opposite sides of center, total distance = d1 + d2 = 12 + 5 = 17 cm.

Multiple choice
  1. ∠OPQ

  2. 2∠ OPQ

  3. 1/2 ∠ OPQ

  4. 1/3∠ OPQ

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

Since TP and TQ are tangents from point T, they are equal in length and OT bisects ∠PTQ. In right triangle OPQ, ∠OPQ is the angle between OP and PQ. The angle ∠PTQ is external to triangle OPQ and equals 2∠OPQ. This is a standard property: the angle between two tangents equals the difference in the arcs they intercept, which is twice the angle in the alternate segment.

Multiple choice
  1. 6 : 7

  2. 12 : 11

  3. 9 : 16

  4. 36 : 49

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

For similar triangles, the ratio of areas equals the square of the ratio of corresponding sides. AB/DE = 1.2/1.4 = 6/7. Therefore, Area(ABC)/Area(DEF) = (6/7)² = 36/49.

Multiple choice
  1. 8 cm/सेमी

  2. 7 cm/सेमी

  3. 6 cm/सेमी

  4. 12 cm/सेमी

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

For two circles with radii r1 and r2 and distance d between centers, the transverse common tangent length = √(d² - (r1 + r2)²) = √(10² - (4.5 + 3.5)²) = √(100 - 64) = √36 = 6 cm.

Multiple choice
  1. 12

  2. 24

  3. 36

  4. 48

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

For two intersecting circles with radii r1=30, r2=40 and distance d=50, the common chord length = 2 × √(r1² - (d² + r1² - r2²)²/(4d²)). Using this formula or noting that 30-40-50 is a right triangle, the perpendicular distance from centers to chord gives chord length = 48 cm.

Multiple choice
  1. 84π

  2. 74π

  3. 75π

  4. 85π

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

Using chord property: The perpendicular from the center to a chord bisects it. Half-chord = 7 cm. In right triangle: r² = 5² + 7² = 25 + 49 = 74. Area = πr² = π × 74 = 74π. (Note: The radius is √74 cm, approximately 8.6 cm, which gives area 74π sq.cm ≈ 232.5 sq.cm).

Multiple choice
  1. (4–π) cm2/सेमी2

  2. 16(4–π) cm2/सेमी2

  3. 8(4–π) cm2/सेमी2

  4. 7(4–π) cm2/सेमी2

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

Original square area = 8² = 64 cm². Four quarter-circles (or one full circle) of radius 4 cm are removed from corners. Area removed = π × 4² = 16π cm². Remaining area = 64 - 16π = 16(4 - π) cm². The key insight is recognizing that four quarter-circles equal one complete circle.