This set of Aptitude Questions and Answers (MCQs) focuses on “Triangles”.

1. What will be the area (in sq. cm) of a triangle having base 13 cm and height 12 cm?

a) 75

b) 66

c) 78

d) 85

View Answer

Explanation: Given,

b = 13 cm, h = 12 cm

➩ Area of triangle = (1 / 2) * b * h

➩ Area of triangle = (1 / 2) * 13 * 12

➩ Area of triangle = 78 cm

^{2}

2. Which of the following is the correct option with respect to the area of a triangle?

a) (1 / 2) * b * h

b) b * h

c) (1 / 3) * b * h

d) (b * h)^{2}

View Answer

Explanation:

Formula of area of triangle = (1 / 2) * b * h.

3. What is the correct formula of the area of an equilateral triangle with side a?

a) (√3 / 4) a

b) (√3 / 4) a^{2}

c) (√3 / 2) a^{2}

d) (√3 / 2) a

View Answer

Explanation:

Formula of area of an equilateral triangle = (√3 / 4) a

^{2}.

4. If the side of an equilateral triangle is doubled then by how many times is its area increased?

a) 4

b) 8

c) 2

d) 16

View Answer

Explanation: Let the original side length = a

Original area = (√3 / 4) a

^{2}

New side length = 2a

New area = (√3 / 4) (2a)

^{2}

= (√3 / 4) 4a

^{2}

Thus, on comparing

New area = 4 * Old area

5. Which of the following is a correct expression regarding area of a triangle ABC?

a) 2abSinC = 2bcSinA = 2acSinB

b) 1 / 2abSinC + 1 / 2bcSinA + 1 / 2acSinB

c) 1 / 2abSinC = 1 / 2bcSinA = 1 / 2acSinB

d) 3 / 4abSinC = 3 / 4bcSinA = 3 / 4acSinB

View Answer

Explanation:

Correct formula for the area of a triangle = 1 / 2abSinC = 1 / 2bcSinA = 1 / 2acSinB.

6. What will be the area of the triangle XYZ if x = 9.7cm, y = 8 cm and Z = 64 degree?

a) 37.8 cm^{2}

b) 29.54 cm^{2}

c) 27.53 cm^{2}

d) 34.53 cm^{2}

View Answer

Explanation: Area of the triangle = 1 / 2xySinz

➩ (1 / 2) (9.7) (8) (Sin64)

➩ (1 / 2) (9.7) (8) (0.89)

➩ 34.53 cm

^{2}

7. What will be the area (in sq. cm) of the triangle ABC if a = 7.8cm, c = 6.8cm and B = 52 degree?

a) 20.68

b) 25.43

c) 15.39

d) 17.64

View Answer

Explanation:

Area of triangle = (1 / 2) ac Sin B

= (1 / 2) * (7.8) * (6.8) * (Sin52)

= (1 / 2) * (7.8) * (6.8) * (0.78)

= 20.68 cm

^{2}

8. If height of a triangle is doubled such that its area remains the same then what will be the measure of its base length?

a) 2b / 3

b) b^{2} / 2

c) b / 2

d) b^{3} / 6

View Answer

Explanation: Let the original base = b, height = h and new base = B.

Area = (1 / 2) * b * h

Area = (1 / 2) * B * 2h

= B * h

On equating both the expressions of area

➩ (1 / 2) * b * h = B * h

➩ b / 2 = B

9. If the area of a square with side x is equal to the area of a triangle with height x then what will be the measure of its base?

a) x^{2}

b) 2x

c) x / 3

d) 2x / 3

View Answer

Explanation: We know that area of square = x

^{2}

Area of triangle = (1 / 2) * b * x

➩ (1 / 2) * b * x = x

^{2}

➩ b = 2x

10. A triangle and a parallelogram are constructed on the same base such that their areas are equal. If the altitude of the parallelogram is 50 m, then what will be the altitude of the triangle?

a) 100 m

b) 125 m

c) 50 m

d) 110 m

View Answer

Explanation: Let the altitude of the triangle = H

Area of triangle = (1 / 2) * b * H

Area of rectangle = b * h

= b * 50

According to the question

➩ (1 / 2) * b * H = b * 50

➩ H = 2 * 50 m

➩ H = 100 m

To practice all aptitude questions, please visit “1000+ Quantitative Aptitude Questions”, “1000+ Logical Reasoning Questions”, and “Data Interpretation Questions”.