Question

1. Find the area of an equilateral triangle, the length of whose sides is 12 cm.
3. Find the area of an isosceles right angled triangle of equal sides 15 cm each.
3. The base and height of a triangle are in the ratio 8:5 and its area is 320 m². Find the​

Answer 1

Step-by-step explanation:

so this is your answer ...

Answer 2

1. side of equi ∆ = 12cm

ar. of equi ∆ = √3/4 × side^2

= √3/4 × 12 × 12

= 36√3 cm^2

= 62.35 cm^2

2.In an isosceles right angled ∆, base and height are same.

So , b = h = 15cm

ar. of ∆ = 1/2 × b×h

= 1/2 × 15 × 15 = 112.5 cm^2

3. let the base and height be 8x and 5x.

ar. of ∆ = 320m^2

1/2 × b×h = 320

1/2 × 8x × 5x = 320

20x^2 = 320

x^2 = 320/20

x^2 = 16

x = √16 = 4

base = 8×4 = 32m

height = 5×4 = 20m