Mathorio
Answer key
Area of Parallelograms
Show your work for each problem.
- 1.What is the formula for the area of a parallelogram?
- a)
- b)
- c)
- d)
Answer:
The area of a parallelogram is base times height: . The second option is addition (not area), the third is perimeter, and the fourth only uses one dimension.
- 2.Find the area of a parallelogram with base 6 cm and height 4 cm.
Answer: 24
cm²
- 3.Which measurement is the height in a parallelogram?
- a)The diagonal
- b)The perpendicular distance from base to opposite side
- c)The length of the slanted side
- d)The perimeter
Answer: The perpendicular distance from base to opposite side
The height is always the perpendicular (90°) distance from the base to the opposite parallel side. It's not the slanted side, perimeter, or diagonal.
- 4.A parallelogram has base 10 m and height 3 m. What is its area?
Answer: 30
m²
- 5.Find the area of a parallelogram with base 7 cm and height 5 cm.
Answer: 35
- What formula do we use for the area of a parallelogram? A = b × h
- Substitute the values: A = ? × ? 7 × 5
- Calculate 7 × 5 35
- 6.A parallelogram has sides of 12 cm and 8 cm. The perpendicular height to the 12 cm base is 6 cm. What is the area?
- a)72 cm²
- b)48 cm²
- c)96 cm²
- d)20 cm²
Answer: 72 cm²
cm². The 8 cm side is not needed for the area calculation.
- 7.A parallelogram has an area of 56 cm² and a base of 8 cm. What is the height?
Answer: 7
Using , we rearrange to cm.
- 8.Find the base of a parallelogram with area 63 m² and height 9 m.
Answer: 7
- Write the area formula A = b × h
- Substitute known values: 63 = b × ? 9
- Solve for b: b = 63 ÷ 9 7
- 9.A parallelogram has base 15 cm and height 8 cm. What is its area?
Answer: 120
cm²
- 10.A parallelogram-shaped tile has base 25 cm and height 20 cm. If you need to cover 1 m², how many tiles do you need?
Answer: 20
- Find the area of one tile in cm²: 25 × 20 = ? 500
- Convert 1 m² to cm²: 1 m² = ? cm² 10000
- Divide: 10000 ÷ 500 = ? 20
- 11.If you double the height of a parallelogram, what happens to the area?
- a)The area doubles
- b)The area is halved
- c)The area quadruples
- d)The area stays the same
Answer: The area doubles
If , then doubling h gives . The area doubles.
- 12.A parallelogram has base 12.5 cm and height 6.4 cm. What is its area?
Answer: 80
cm²
- 13.Two parallelograms have the same area. One has base 16 cm and height 9 cm. The other has base 12 cm. What is the height of the second parallelogram?
Answer: 12
- Find the area of the first parallelogram: 16 × 9 = ? 144
- The second parallelogram has the same area. What is it? 144
- Find height: h = 144 ÷ 12 = ? 12
- 14.A parallelogram has base 20 m and one side of 15 m. If the perpendicular height to the base is 12 m, what is the area?
- a)300 m²
- b)35 m²
- c)240 m²
- d)180 m²
Answer: 240 m²
m². The 15 m side is extra information.
- 15.A garden in the shape of a parallelogram has an area of 180 m². If the base is 15 m, what is the height? Then, if fencing costs 8 euros per meter and you need to fence two sides of height, how much does the fencing cost?
Answer: 192
- Find the height: h = 180 ÷ 15 = ? 12
- Calculate total fencing needed: 2 × height = 2 × 12 = ? 24
- Calculate cost: 24 × 8 = ? 192
- 16.A parallelogram-shaped field has an area of 2400 m². If a farmer wants to divide it into 6 equal parallelogram plots, what is the area of each plot?
Answer: 400
Each plot: m²
- 17.True or False: A rectangle is a special type of parallelogram.
- a)True
- b)Only if it's a square
- c)False
- d)Only sometimes
Answer: True
True! A rectangle has two pairs of parallel sides, just like a parallelogram. It's a parallelogram where all angles are 90°.
- 18.A sail on a boat is shaped like a parallelogram. The base is 3.5 m and the height is 4 m. What is the sail's area?
Answer: 14
- Write the formula for area A = b × h
- Substitute: A = 3.5 × ? 4
- Calculate: 3.5 × 4 = ? 14