Calculate the full perimeter of a semicircle with a diameter 8cm. Round to 1 decimal place.

20.6 cm

Step-by-step explanation:

First find the circumference of a semicircle with diameter 8 cm

C = 1/2 ( pi d)

C = 1/2 ( 3.14 * 8)

C = 12.56cm

Then add the diameter to close the circle

12.56+8 = 20.56 cm

Round to 1 decimal place

20.6 cm

b. an equilateral triangle inscribed in a circle

step-by-step explanation:

we are given the figure of two circles having a triangle inside.

now, we know that,

"when a figure is lying inside an another figure, then the outside figure is known as circumscribed figure and the figure lying inside is referred to as the inscribed figure".

as we see that, the circles are containing the triangle completely.

thus, the circles are the circumscribed figures and the triangle is the inscribed figure.

hence, we get, 'an equilateral triangle is inscribed in a circle'.