Question

Geometry help

Answer 1

http://www.mathwarehouse.com/trigonometry/area/side-angle-side-triangle.php

Answer 2

@vivianrush Did you get the answer to number 4 to be 9.8 as shown on the diagram?

Answer 3

oh no i didn't. i didn't noice i clicked an answer. I keep getting odd answers. I don't know what I'm doing wrong tho. a=1/2bh

Answer 4

click the link...
it gives you the area formula, the one you're using only applies to right triangles

Answer 5

well not exactly

Answer 6

It is true that the area of a triangle is 1/2 a base length times the corresponding height but here you need trig. The formula that @completeidiot has linked is the one.

Answer 7

Think of the theorem as this: The area of any triangle is (1/2) the product of any two sides and the sine of the included angle.

Answer 8

For problem four,

A = (1/2) * (4.7) * (6.1) * (sin (47 degrees)

See what you get for that calculation. Be sure your calculator is set for degrees.

@vivianrush

Answer 9

i got 14.3

Answer 10

I went with the "Wolf" at WolframAlpha and got a different answer.

(1/2) * (4.7) * (6.1) * (sin (47 degrees)) = 10.48 approx

I checked with mental math and got approximately the same answer.

Do you want to show your work?

Answer 11

i forgot to use the sin key i got 10.48

Answer 12

other one is 63.4

Answer 13

1.For questions 1–2, find the area of the regular polygon. Give the answer to the nearest tenth.

decagon with a side of 4 cm

123.1 cm2
129.4 cm2
246.2 cm2
139.8 cm2

2.pentagon with a side of 10 cm

344.1 cm2
34.4 cm2
137.6 cm2
172 cm2

Answer 14

now what area forlum do i use for these two?

Answer 15

I am still on number 5.
Please post one question per thread.
You will get quicker help that way.

A = (1/2)* 9 * 15*sin(70)

Answer 16

I agree with you on number 5.

Answer 17

Problems 1 and 2 have several parts to the solutions. Use Area = (1/2)*apothem*perimeter

Answer 18

what numbers am i used? 1/2 and 4 i know for sure