30. each interior angle of a regular polygon is 4 times each exterior ang
(a) find the size of each exterior angle of the polygon.
(b) find the number of sides of the polygon.

(a) the size of each exterior angle  360/10=36

(b)  the number of sides of the polygon. 10

Step-by-step explanation:

Each interior angle of a regular polygon is 4 times each exterior angle

∴sum of interior angles: (n-2)*180=4*360

n-2=8

n=10

(a) the size of each exterior angle  360/10=36

(b)  the number of sides of the polygon. 10

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'.