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Trapeziums Sectors and Composite Figures — Free MYP4 Mathematics (Standard) Practice Questions
1QuestionArea of Circular Sectors and SegmentsConcept Practice
2 marks~3 minCriterion A
A circle has centre O and radius r. Sector OAB has central angle θ°.
a
Explain why sector OAB represents the fraction 360θ of the full circle. [1]
b
Justify why the area of sector OAB is given by A=360θ×πr2. [1]
Solutions
2QuestionArea of Circular Sectors and SegmentsAssessment Practice
5 marks~8 minCriterion B
A circle has radius r and centre O. A sector of the circle has central angle θ°.
a
State the arc length of the sector and the area of the full circle. [1]
b
A sector is dissected into many thin triangular strips, each with vertex at O, height approximately r, and base along the arc. The strips are rearranged into a shape that approximates a rectangle. Show that the area of the sector is 360θπr2. [2]
c
A designer claims that a sector with θ=120° and r=8 cm has sufficient area to cover a surface of 165cm2. Assess whether this claim is correct, justifying your answer with a calculation. [2]
Solutions
3QuestionArc Length and Sector Area CalculationsAssessment Practice
6 marks~9 minCriterion D
A landscape architect is designing a circular fountain with a radius of 2.5 m. A sector with a central angle of 120° will be decorated with tiles. The client's budget allows for exactly 6.5 m² of tiling. The architect's radius measurements have a tolerance of ±0.1 m, and tile grout reduces the effective tiled area by 2%.
a
Calculate the area of the 120° sector using
A=360θπr2
where θ is the central angle in degrees. [2]
b
Deduce whether the sector area exceeds the budget, stating the difference. [1]
c
Advise the architect whether the design is feasible within the budget, justifying your recommendation by considering the effect of the radius tolerance on the calculated area and the impact of grout on the effective tiled area. [3]
Solutions
4QuestionArc Length and Sector Area CalculationsAssessment Practice
6 marks~9 minCriterion C
A landscape architect is designing decorative stone edging for four circular garden beds. Each bed uses a sector of stone with an arc length of 10 cm per unit scale. The sectors have radii of 3 cm, 6 cm, 9 cm, and 12 cm respectively.
The perimeter of a sector is given by P=L+2r, where L is the arc length and r is the radius.
a
Calculate the perimeter of each sector. Record your results as ordered pairs (r,P) in order of increasing radius. [2]
b
Deduce the perimeter of a sector with radius 15 cm and the same arc length. Justify your reasoning using the pattern in your results. [2]
c
The architect claims that doubling the radius of a sector always produces a more efficient design because the perimeter does not double. Assess this claim using the formula P=L+2r, and interpret what this means for the architect's choice of sector size. [2]