Saved Bookmarks
| 1. |
The height of an equilateral triangle measures 9 cm. Find its area, correct to 2 places of decimal. (Take √3 = 1.732) |
|
Answer» Consider a as the side of an equilateral triangle We know that Height of an equilateral triangle = √3/2 a It is given that height = 9cm So we get √3/2 a = 9 On further calculation a = (9 × 2)/ √3 Multiplying both numerator and denominator by √3 We get a = (9 × 2 × √3) / (√3 × √3) So we get Base = a = 6√3cm We know that the area of an equilateral triangle = ½ × b × h By substituting the values Area of the equilateral triangle = ½ × 6√3 × 9 On further calculation Area of the equilateral triangle = 27√3 cm2 By substituting the value of √3 Area of the equilateral triangle = 27 × 1.732 = 46.764 By correcting to 2 places of decimal Area of the equilateral triangle = 46.76 cm2 Therefore, the area of an equilateral triangle = 46.76 cm2. |
|