Find the area and perimeter of abc at right. give approximate (decimal) answers, not exact answers

Area of Δ ABC = 21.86 units square

Perimeter of Δ ABC = 24.59 units

Step-by-step explanation:

Given:

In Δ ABC

∠A=45°

∠C=30°

Height of triangle = 4 units.

To find area and perimeter of triangle we need to find the sides of the triangle.

Naming the end point of altitude as 'O'

Given

For Δ ABO

Since its a right triangle with one angle 45°, it means it is a special 45-45-90 triangle.

The sides of 45-45-90 triangle is given as:

We are given BO (Leg 1)

∴ AO (Leg2)

∴ AB (hypotenuse)  

For Δ CBO

Since its a right triangle with one angle 30°, it means it is a special 30-60-90 triangle.

The sides of 30-60-90 triangle is given as:

We are given BO (side opposite 30° angle)

CO (side opposite 60° angle)

BC (Hypotenuse)

Length of side AC is given as sum of AO and CO

Perimeter of Δ ABC= Sum of sides of triangle

⇒ AB+BC+AC

⇒

⇒ units

Area of Δ ABC =

⇒  

⇒ units square

an = 22 + (n-1) *6

110 seats

step-by-step explanation:

an=a1+(n-1)(d)

a1 = 22   this is the first item in the sequence

d =6   this is how the sequence goes up

a)   an = 22 + (n-1) *6

b) a12 = 22 + (12-1) *6

    a12 = 22+11*6

  a12 = 22 +88

  a12 = 110