Sasi Math (Revised for 1024)

Scroll:Measurement >> Area of Triangle >> ps (1314)

Written Instructions:

For each Multiple Choice Question (MCQ), four options are given. One of them is the correct answer. Make your choice (1,2,3 or 4). Write your answers in the brackets provided..

For each Short Answer Question(SAQ) and Long Answer Question(LAQ), write your answers in the blanks provided.

Leave your answers in the simplest form or correct to two decimal places.

ABCD is a rectangle of area 112cm² . B and F are midpoints of AC and AE respectively.

Find the area of the shaded triangle.

cm²

Answer:_______________

ABCD is a square of area 36cm² . E and F are midpoints of AD and AB respectively.

Find the area of the shaded triangle.

cm²

Answer:_______________

ABCD is a rectangle of area 240cm² . B and F are midpoints of AC and AE respectively.

Find the area of the shaded triangle.

cm²

Answer:_______________

ABCD is a square of area 64cm² . E and F are midpoints of AD and AB respectively.

Find the area of the shaded triangle.

cm²

Answer:_______________

ABCD is a rectangle of area 200cm² . B and F are midpoints of AC and AE respectively.

Find the area of the shaded triangle.

cm²

Answer:_______________

ABCD is a square of area 144cm² . E and F are midpoints of AD and AB respectively.

Find the area of the shaded triangle.

cm²

Answer:_______________

ABCD is a rectangle of area 168cm² . B and F are midpoints of AC and AE respectively.

Find the area of the shaded triangle.

cm²

Answer:_______________

ABCD is a square of area 100cm² . E and F are midpoints of AD and AB respectively.

Find the area of the shaded triangle.

cm²

Answer:_______________

ABCD is a rectangle of area 80cm² . B and F are midpoints of AC and AE respectively.

Find the area of the shaded triangle.

cm²

Answer:_______________

10)

ABCD is a square of area 16cm² . E and F are midpoints of AD and AB respectively.

Find the area of the shaded triangle.

cm²

Answer:_______________

ABCD is a rectangle of area 112cm² . B and F are midpoints of AC and AE respectively.

Find the area of the shaded triangle.

Answer: 42 cm²

SOLUTION 1 :

2 cm

28 cm

Step 1: Area of rectangle ACDE → 28 cm x 4 cm = 112 cm²

Step 2: Length of AB → 28 cm ÷ 2 = 14 cm

Step 3: Lenght of AF → 4 cm ÷ 2 = 2 cm

Step 4: Area of triangle ABF → $\frac{1}{2}$ x 14 cm x 2 cm = 14 cm²

Step 5: Area of triangle CDB → $\frac{1}{2}$ x 14 cm x 4 cm = 28 cm²

Step 6: Area of triangle DEF → $\frac{1}{2}$ x 28 cm x 2 cm = 28 cm²

Step 7: 14 cm² + 28 cm² + 28 cm² = 70cm²

Step 8: Area of shaded triangle → 112 cm² - 70 cm² = 42 cm²

ABCD is a square of area 36cm² . E and F are midpoints of AD and AB respectively.

Find the area of the shaded triangle.

Answer: 13.5 cm²

SOLUTION 1 :

3 cm

6 cm

Step 1: Area of square ABCD → 6 cm x 6 cm = 36 cm²

Step 2: Length of AF → 6 cm ÷ 2 = 3 cm

Step 3: Area of triangle AFE → $\frac{1}{2}$ x 3 cm x 3 cm = 4.5 cm²

Step 4: Area of triangle CDE → $\frac{1}{2}$ x 3 cm x 6 cm = 9 cm²

Step 5: Area of triangle CBF → $\frac{1}{2}$ x 3 cm x 6 cm = 9 cm²

Step 6: 4.5 cm² + 9 cm² + 9 cm² = 22.5cm²

Step 7: 36 cm² - 22.5 cm² = 13.5 cm²

ABCD is a rectangle of area 240cm² . B and F are midpoints of AC and AE respectively.

Find the area of the shaded triangle.

Answer: 90 cm²

SOLUTION 1 :

5 cm

24 cm

Step 1: Area of rectangle ACDE → 24 cm x 10 cm = 240 cm²

Step 2: Length of AB → 24 cm ÷ 2 = 12 cm

Step 3: Lenght of AF → 10 cm ÷ 2 = 5 cm

Step 4: Area of triangle ABF → $\frac{1}{2}$ x 12 cm x 5 cm = 30 cm²

Step 5: Area of triangle CDB → $\frac{1}{2}$ x 12 cm x 10 cm = 60 cm²

Step 6: Area of triangle DEF → $\frac{1}{2}$ x 24 cm x 5 cm = 60 cm²

Step 7: 30 cm² + 60 cm² + 60 cm² = 150cm²

Step 8: Area of shaded triangle → 240 cm² - 150 cm² = 90 cm²

ABCD is a square of area 64cm² . E and F are midpoints of AD and AB respectively.

Find the area of the shaded triangle.

Answer: 24 cm²

SOLUTION 1 :

4 cm

8 cm

Step 1: Area of square ABCD → 8 cm x 8 cm = 64 cm²

Step 2: Length of AF → 8 cm ÷ 2 = 4 cm

Step 3: Area of triangle AFE → $\frac{1}{2}$ x 4 cm x 4 cm = 8 cm²

Step 4: Area of triangle CDE → $\frac{1}{2}$ x 4 cm x 8 cm = 16 cm²

Step 5: Area of triangle CBF → $\frac{1}{2}$ x 4 cm x 8 cm = 16 cm²

Step 6: 8 cm² + 16 cm² + 16 cm² = 40cm²

Step 7: 64 cm² - 40 cm² = 24 cm²

ABCD is a rectangle of area 200cm² . B and F are midpoints of AC and AE respectively.

Find the area of the shaded triangle.

Answer: 75 cm²

SOLUTION 1 :

5 cm

20 cm

Step 1: Area of rectangle ACDE → 20 cm x 10 cm = 200 cm²

Step 2: Length of AB → 20 cm ÷ 2 = 10 cm

Step 3: Lenght of AF → 10 cm ÷ 2 = 5 cm

Step 4: Area of triangle ABF → $\frac{1}{2}$ x 10 cm x 5 cm = 25 cm²

Step 5: Area of triangle CDB → $\frac{1}{2}$ x 10 cm x 10 cm = 50 cm²

Step 6: Area of triangle DEF → $\frac{1}{2}$ x 20 cm x 5 cm = 50 cm²

Step 7: 25 cm² + 50 cm² + 50 cm² = 125cm²

Step 8: Area of shaded triangle → 200 cm² - 125 cm² = 75 cm²

ABCD is a square of area 144cm² . E and F are midpoints of AD and AB respectively.

Find the area of the shaded triangle.

Answer: 54 cm²

SOLUTION 1 :

6 cm

12 cm

Step 1: Area of square ABCD → 12 cm x 12 cm = 144 cm²

Step 2: Length of AF → 12 cm ÷ 2 = 6 cm

Step 3: Area of triangle AFE → $\frac{1}{2}$ x 6 cm x 6 cm = 18 cm²

Step 4: Area of triangle CDE → $\frac{1}{2}$ x 6 cm x 12 cm = 36 cm²

Step 5: Area of triangle CBF → $\frac{1}{2}$ x 6 cm x 12 cm = 36 cm²

Step 6: 18 cm² + 36 cm² + 36 cm² = 90cm²

Step 7: 144 cm² - 90 cm² = 54 cm²

ABCD is a rectangle of area 168cm² . B and F are midpoints of AC and AE respectively.

Find the area of the shaded triangle.

Answer: 63 cm²

SOLUTION 1 :

3 cm

28 cm

Step 1: Area of rectangle ACDE → 28 cm x 6 cm = 168 cm²

Step 2: Length of AB → 28 cm ÷ 2 = 14 cm

Step 3: Lenght of AF → 6 cm ÷ 2 = 3 cm

Step 4: Area of triangle ABF → $\frac{1}{2}$ x 14 cm x 3 cm = 21 cm²

Step 5: Area of triangle CDB → $\frac{1}{2}$ x 14 cm x 6 cm = 42 cm²

Step 6: Area of triangle DEF → $\frac{1}{2}$ x 28 cm x 3 cm = 42 cm²

Step 7: 21 cm² + 42 cm² + 42 cm² = 105cm²

Step 8: Area of shaded triangle → 168 cm² - 105 cm² = 63 cm²

ABCD is a square of area 100cm² . E and F are midpoints of AD and AB respectively.

Find the area of the shaded triangle.

Answer: 37.5 cm²

SOLUTION 1 :

5 cm

10 cm

Step 1: Area of square ABCD → 10 cm x 10 cm = 100 cm²

Step 2: Length of AF → 10 cm ÷ 2 = 5 cm

Step 3: Area of triangle AFE → $\frac{1}{2}$ x 5 cm x 5 cm = 12.5 cm²

Step 4: Area of triangle CDE → $\frac{1}{2}$ x 5 cm x 10 cm = 25 cm²

Step 5: Area of triangle CBF → $\frac{1}{2}$ x 5 cm x 10 cm = 25 cm²

Step 6: 12.5 cm² + 25 cm² + 25 cm² = 62.5cm²

Step 7: 100 cm² - 62.5 cm² = 37.5 cm²

ABCD is a rectangle of area 80cm² . B and F are midpoints of AC and AE respectively.

Find the area of the shaded triangle.

Answer: 30 cm²

SOLUTION 1 :

2 cm

20 cm

Step 1: Area of rectangle ACDE → 20 cm x 4 cm = 80 cm²

Step 2: Length of AB → 20 cm ÷ 2 = 10 cm

Step 3: Lenght of AF → 4 cm ÷ 2 = 2 cm

Step 4: Area of triangle ABF → $\frac{1}{2}$ x 10 cm x 2 cm = 10 cm²

Step 5: Area of triangle CDB → $\frac{1}{2}$ x 10 cm x 4 cm = 20 cm²

Step 6: Area of triangle DEF → $\frac{1}{2}$ x 20 cm x 2 cm = 20 cm²

Step 7: 10 cm² + 20 cm² + 20 cm² = 50cm²

Step 8: Area of shaded triangle → 80 cm² - 50 cm² = 30 cm²

10)

ABCD is a square of area 16cm² . E and F are midpoints of AD and AB respectively.

Find the area of the shaded triangle.

Answer: 6 cm²

SOLUTION 1 :

2 cm

4 cm

Step 1: Area of square ABCD → 4 cm x 4 cm = 16 cm²

Step 2: Length of AF → 4 cm ÷ 2 = 2 cm

Step 3: Area of triangle AFE → $\frac{1}{2}$ x 2 cm x 2 cm = 2 cm²

Step 4: Area of triangle CDE → $\frac{1}{2}$ x 2 cm x 4 cm = 4 cm²

Step 5: Area of triangle CBF → $\frac{1}{2}$ x 2 cm x 4 cm = 4 cm²

Step 6: 2 cm² + 4 cm² + 4 cm² = 10cm²

Step 7: 16 cm² - 10 cm² = 6 cm²