# triangle help

• Jun 5th 2012, 12:52 AM
Domicro
triangle help
Hi. I've just got 20 math tasks that I need to solve until saturday. I don't know how to solve 4. Pls help. P. S. My english is not very good, sorry about that..
1. Man and woman are standing on the street. A man is tall 188 cm and his shadow is tall 1 m (100cm).. How tall is the woman if her shadow is 80 cm tall.
2. Area (surface) of similar triangels is 8cm2 and 18cm2. If extent (perimeter) of bigget triangle is 20cm, what's the extent (perimeter) of smaller triangle?
3. a= 28 cm, b = 52/3 cm, c = 80/3 cm. What's the radius of circular of his similar triangle if his extent (perimeter) is 126 cm2
4. In right-angeled triangle p = 3cm v = 4 cm. calculate a, b, c. (p=extent (perimeter) and v=height of the triangle)
• Jun 5th 2012, 12:58 AM
Prove It
Re: triangle help
Quote:

Originally Posted by Domicro
4. In right-angeled triangle p = 3cm v = 4 cm. calculate a, b, c. (p=extent (perimeter) and v=height of the triangle)[/FONT][/COLOR]

How could the perimeter of the triangle be less than one of the lengths?

I expect you meant that the base length was 3cm and the height was 4cm. Since it's a right angle triangle, you can use Pythagoras' Theorem to find the third length.
• Jun 6th 2012, 01:06 PM
earboth
Re: triangle help
Quote:

Originally Posted by Domicro
Hi. I've just got 20 math tasks that I need to solve until saturday. I don't know how to solve 4. Pls help. P. S. My english is not very good, sorry about that..
1. Man and woman are standing on the street. A man is tall 188 cm[COLOR=#333333][FONT=arial] and his shadow is tall 1 m (100cm).. How tall is the woman if her shadow is 80 cm tall.

...

Draw a sketch. Use proportions.

$\frac{length\ of\ woman}{length\ of\ man}=\frac{length\ of\ woman's\ shadow}{length\ of\ man's\ shadow}$

$\frac w{188}=\frac{80}{100}$

Solve for w.