FINDING THE AREA OF TRIANGLE WITH BASE AND HEIGHT

In the above figure, ABC is a triangle.

The formula to find the area of any triangle is 

Area of a triangle = 1/2 × base × height

In figure, AB = base and CD = height

Area = 1/2 × AB × CD

Problem 1 :

Solution :

Given, base = 6 km

Height = 6 km

Area of triangle = 1/2 × b × h

= 1/2 × 6 × 6

= 18 km²

So, the area of triangle is 18 km².

Problem 2 :

Solution :

Given, base = 9 cm

Height = 2 cm

Area of triangle = 1/2 × b × h

= 1/2 × 9 × 2

= 9 cm²

So, the area of triangle is 9 cm².

Problem 3 :

Solution :

Given, base = 12 cm

Height = 3 cm

Area of triangle = 1/2 × b × h

= 1/2 × 12 × 3

= 18 cm²

So, the area of triangle is 18 cm².

Problem 4 :

Solution :

Given, base = 15 m

Height = 12 m

Area of triangle = 1/2 × b × h

= 1/2 × 15 × 12

= 90 m²

So, the area of triangle is 90 m².

Problem 5 :

Solution :

Given, base = 10.7 km

Height = 3.4 km

Area of triangle = 1/2 × b × h

= 1/2 × 10.7 × 3.4

= 18.19 km²

So, the area of triangle is 18.19 km².

Problem 6 :

Solution :

Given, base = 24 ½ ft = 49/2 ft

Height = 8 ft

Area of triangle = 1/2 × b × h

= 1/2 × 49/2 × 8

= 98 ft²

So, the area of triangle is 98 ft².

Find the missing dimension.

Problem 7 :

Base: 4 in

Area: 22 in²

Solution:

Area of triangle = 1/2 × b × h

22 = 1/2 × 4 × h

22 = 2h

h = 11 in

So, the height of triangle is 11 in.

Problem 8 :

Height: 1 yd

Area = 2.5 yd²

Solution :

Area of triangle = 1/2 × b × h

2.5 = 1/2 × b × 1

2.5 = b/2

b = 5 yd

So, the base of triangle is 5 yd.

Problem 9 :

Base: 5 ft

Area: 5 5/6 ft² = 35/6 ft²

Solution :

Area of triangle = 1/2 × b × h

35/6 = 1/2 × 5 × h

35/6 = 5/2 × h

h = (35/6) × (2/5)

h = 7/3 ft

So, the height of triangle is 7/3 ft.