# easy geometry

posted by cyrus

1)If diagonals of a rhombus are 10 cm and 24 cm. find the area and perimeter of the rhombus.
2)A regular hexagon with a perimeter of 24 units is inscribed in a circle. Find the radius of the circle.
3)Find the altitude,perimeter and area of an isosceles trapezoid whose sides have lengths 10 cm, 20 cm, 10 cm and 30 cm.
4) The consecutive sides of a quadrilateral measure (x-17), (24-x), (3x-40) and (x+1). the perimeter is 42 cm. Is the quadrilateral a parallelogram?
5)The perimeter of parallelogram QUAD is 10 more than 5 times AU. If QU = 26 cm. Find AU.

Thanks for those who will share their solutions. God bless!

1. Reiny

1. In a rhombus, the diagonals bisect each other at right angles. So you have 4 congruent right-angled triangles with sides 5 and 12, and the hypotenuse is the side of the rhombus.
s^2 = 5^2 + 12^2
(You should recognize that Pythagorean triple, if not, remember it)
Find the area of one triangle, then multiply by 4

2. There are 6 identical isosceles triangle with a base of 24/6 or 4 units, and a central angle of 60°

3. I drew a figure ABCD , with AD || BC
AB = 20
BC = 30, and
CD = 10
From A draw a line AP, so that AP is || to DC and P is on BC
So AP=10 and APCD Is a rhombus (all sides = 10)
Now look at triangle ABP , it is isosceles with sides 20,20, and 10
We need an angle, I found angle APB
cos APB =5/20
angle APB = appr 75.52°
So angle APC = 104.48°
Take it from there.

2. Reiny

x-17 + 24-x + 3x-40 + x+1 = 42
4x = 74
x = 18.5 ,
so the sides are 1.5 , 5.5, 15.5 , and 19.5
how about doubling each side, creating a "similar" quadrilateral, (angles won't change)

3 , 11 , 31 , and 39 , mmmh, what do you know about sides of a parallelogram ?

#5
Make your sketch, label QU = 26 , let AU = x
we know
perimtetr = x + 26 + x + 26
= 2x + 52
but 2x + 52 = 5x + 10
3x = 42
x = 14

So AU = 14 cm

3. cyrus

Thanks Mr.Reiny! But I don't understand your solution in number 3. Can you show another, please.

4. Nerd

Not sure

## Similar Questions

1. ### math-geometry

1. A rhombus has a perimeter of 96, and the length of one of its diagonals is 32. The area of the circle inscribed in the rhombus can be expressed as k*pi/w where k and w are relatively prime positive integers. Find the value of k …

1. A rhombus has a perimeter of 96, and the length of one of its diagonals is 32. The area of the circle inscribed in the rhombus can be expressed as k*pi/w where k and w are relatively prime positive integers. Find the value of k …
3. ### geometry

The diagonals of a rhombus are in 2:1. If the perimeter of the rhombus is 120cm, find the length of the diagonals.
4. ### easy GEOMETRY!!

1.The perimeter of parallelogram QUAD is 10 more than 5 times AU. If QU =26 cm. find AU 2.If diagonals of a rhombus are 10 cm and 24 cm. find the area and perimeter of the rhombus SOlutions pleaseeeeeee
5. ### GEOMETRY

A. A regular hexagon with a perimeter of 24 units is inscribed in a circle. Find the radius of the circle. B . Find a relationship between the areas of triangle ADC and parallelogram ABCD this is our assignment for tomorrow . . its …
6. ### geometry

1.The perimeter of parallelogram QUAD is 10 more than 5 times AU. If QU =26 cm. find AU 2.If diagonals of a rhombus are 10 cm and 24 cm. find the area and perimeter of the rhombus SOlutions pleaseeeeeee
7. ### geometry

A regular hexagon with a perimeter of 24 units is inscribed in a circle. Find the radius of the circle.
8. ### Maths

The diagonals of a rhombus are in the ratio 3:4. If its perimeter is 40 cm, find the lengths of the sides and diagonals of the rhombus
9. ### maths

The diagonals of a rhombus are in the ratio 3:4. If its perimeter is 40 cm, find the lengths of the sides and diagonals of the rhombus
10. ### Math

the diagonals of a rhombus are in the ratio 3:4. if its perimeter is 40cm then find the length of the sides and diagonals of the rhombus

More Similar Questions