Geometry Questions

Multiple choice
  1. 2.8 cm

  2. 2.5 cm

  3. 3.2 cm

  4. 3 cm

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

In a circle, the perpendicular from the center to a chord bisects the chord. QR is a chord. Since PQ=PR=12, triangle PQR is isosceles. PO is the perpendicular bisector of QR. Using Pythagoras in triangle OMQ (where M is midpoint of PQ), find the distance.

Multiple choice
  1. 1

  2. 2

  3. 3

  4. 4

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

Circle 1: center (2, 3), radius = sqrt(4+9+12) = 5. Circle 2: center (-3, -9), radius = sqrt(9+81-26) = 8. Distance between centers = sqrt((2 - -3)^2 + (3 - -9)^2) = sqrt(5^2 + 12^2) = 13. Since distance (13) = r1 + r2 (5 + 8), the circles touch externally. They have 3 common tangents.

Multiple choice
  1. if statement (1) alone is sufficient but statement (2) alone is not

  2. if statement (2) alone is sufficient but statement (1) alone is not

  3. if both (1) and (2) together are sufficient but none of them alone is sufficient

  4. if both statements are sufficient independently

  5. if both (1) and (2) together are not sufficient

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

A parallelogram inscribed in a circle must be a rectangle. The diagonal of the rectangle is the diameter of the circle. Statement (2) gives the area of the circle (pi * r^2 = 169 * pi), so r = 13, diameter = 26. With one side = 5, the other side is sqrt(26^2 - 5^2) = sqrt(676 - 25) = sqrt(651). Perimeter = 2 * (5 + sqrt(651)). Both statements are required.

Multiple choice
  1. 8 cm2

  2. 16 cm2

  3. 24 cm2

  4. 32 cm2

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

Centroid divides a triangle into 3 smaller triangles of equal area. Each of triangles BGC, CGA, AGB has area = (1/3) × area of ABC = 48/3 = 16 cm². This is because all three have equal base lengths on the sides of ABC and share the same height from G.

Multiple choice
  1. 6 cm

  2. 7 cm

  3. 10 cm

  4. 8 cm

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

The chord of the larger circle (radius 5 cm) that touches the smaller circle (radius 3 cm) is tangent to it. The distance from the center to the chord equals the smaller radius (3 cm). Using the chord length formula: 2√(r² - d²) = 2√(25 - 9) = 2√16 = 2(4) = 8 cm.

Multiple choice
  1. 3

  2. 6

  3. 5

  4. 2

  5. None of these

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

In a triangle, the centroid divides the median in ratio 2:1 (from vertex). AM is a median of length 9. The centroid is at distance (2/3) × 9 = 6 from A. Point N is on AM with MN = 1, so N is at distance 9 - 1 = 8 from A. Distance from N to centroid = 8 - 6 = 2.

Multiple choice
  1. 300

  2. 400

  3. 500

  4. 600

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

In any triangle, the angle at the center (circumcentre) is twice the angle at the circumference subtended by the same arc. Given ∠BAC = 50°, the central angle ∠BOC = 2 × 50° = 100°. Since O is the circumcentre, OB = OC (both are radii), so triangle OBC is isosceles. Therefore, ∠OBC = (180° - 100°)/2 = 40°. This uses the central angle theorem and properties of isosceles triangles.