Geometry Questions
1. Problem: One angle of a triangle is 70°. The other two angles are in the ratio 3:2. Find the measure of the other two angles.
Step 1: Let the other two angles be $3x$ and $2x$.
Step 2: Sum of angles in a triangle is $180^\circ$.
Step 3: Write equation: $70 + 3x + 2x = 180$.
Step 4: Simplify: $5x = 110 \Rightarrow x = 22$.
Step 5: Find angles: $3x = 66^\circ$, $2x = 44^\circ$.
Answer: (c) 66°, 44°.
2. Problem: Identify the equilateral triangle among (a) ACE, (b) BCE, (c) CBD, (d) ABD.
Step 1: Equilateral triangle has all sides equal.
Step 2: From figure, triangle ACE has all sides equal.
Answer: (a) ACE.
3. Problem: Find measure of angle ∠ADB if AB is a straight line.
Step 1: Straight line angle is $180^\circ$.
Step 2: Given angles and figure show ∠ADB = $115^\circ$.
Answer: (b) 115°.
4. Problem: Find measure of angle ∠CAB.
Step 1: From figure and given data, ∠CAB = $50^\circ$.
Answer: (b) 50°.
5. Problem: Identify an angle of quadrilateral AFCB among ∠1, ∠2, ∠3, ∠4.
Step 1: Quadrilateral angles are at vertices A, F, C, B.
Step 2: From figure, ∠3 is an angle of AFCB.
Answer: (c) ∠3.
6. Problem: Find ∠BFC if ∠FBC = ∠FCB = 75°.
Step 1: Triangle BFC has angles summing to $180^\circ$.
Step 2: Calculate ∠BFC = $180 - 75 - 75 = 30^\circ$.
Answer: (d) 30°.
7. Problem: Identify a sector of the circle with center O among (a) ACB, (b) BC, (c) COB, (d) AO.
Step 1: A sector is area bounded by two radii and an arc.
Step 2: Segment COB is bounded by radii OC and OB and arc CB.
Answer: (c) COB.
8. Problem: Which statement is true?
(a) Chord AC is bigger than chord BC.
(b) The biggest chord of the circle is double the length of OC.
(c) AB = 2AC.
(d) OC and CB are radii.
Step 1: OC and CB are radii as they connect center O to circumference.
Step 2: The biggest chord is diameter, which is double radius OC.
Step 3: Chord AC and BC lengths depend on figure; cannot confirm (a) or (c) without data.
Answer: (b) and (d) are true; since only one choice allowed, (d) OC and CB are radii.
9. Problem: Count rectangles and squares in figure 1.
Step 1: Given options: 4, 16, 20, 36.
Step 2: Counting all rectangles and squares formed by grid lines yields 36.
Answer: (d) 36.
10. Problem: Count rectangles and squares in figure 2.
Step 1: Given options: 4, 6, 8, 12.
Step 2: Counting all quadrilaterals formed yields 8.
Answer: (c) 8.
Summary:
1. (c) 66°, 44°
2. (a) ACE
3. (b) 115°
4. (b) 50°
5. (c) ∠3
6. (d) 30°
7. (c) COB
8. (d) OC and CB are radii
9. (d) 36
10. (c) 8