1.One side of a triangle is 5 meters longer than the second side.The third side is four times the length of the second side.If the perimeter of the triangle is 63 meters,how long is the second sides?
2.The sum of two angles in a triangle totals 117 degrees,what is the measure of the third angle?
3.Find the area of a triangle with base 21 inches and height 8 inches.
2007-12-26 10:41:28 · 6 answers · asked by Anonymous in Science & Mathematics ➔ Mathematics
1. There are three sides to your triangle: a, b and c.
b = a + 5 according to the first sentence.
c = 4b according to the second sentence.
a + b + c = 63 according to the question.
a + a + 5 + 4a + 20 = 63
6a + 25 = 63
6a = 38
a = 6 1/3
So, the second side is 6 1/3 + 5 = 11 1/3 m
2. The angles of a triangle add up to 180°
180 - 117 = 63°
3. A = 1/2 (base)(height) = 1/2 * 8 * 21 = 84 sq. in.
2007-12-26 10:49:31 · answer #1 · answered by lhvinny 7 · 0⤊ 0⤋
1) Let x = length of the second side in m
=> x + 5 = length of the first side
and 4x = length of the third side
Perimeter = x + x + 5 + 4x = 63
=> 6x = 58
=> x = 58/6 = 29/3 m
2) Third angle = 180 - 117 = 63 degrees
3) Area = (1/2) base x height
= (1/2) x 21 x 8 = 84 sq. in.
2007-12-26 10:50:18 · answer #2 · answered by Madhukar 7 · 0⤊ 0⤋
Let x = length of side 2
Let x+5 = length of side 1
let 4x = length of side 3
x+(x+5) +4x= 63
6x+5=63
6x=58
x=29/3 cm = 9 2/3cm
side 1 = 14 2/3cm
side 3 = 38 2/3cm
2007-12-26 11:01:15 · answer #3 · answered by saejin 4 · 0⤊ 0⤋
1. x= second side
side 1= x+5
side 3= 4x
so x+x+5+4x=63
6x= 58
x=9.66
2. 180-117= 63 degrees
3. 1/2bh
168/2
= 84 in^2
2007-12-26 10:51:29 · answer #4 · answered by golffan137 3 · 0⤊ 0⤋
1. ?
2. 63
3.84 inches
2007-12-26 10:47:01 · answer #5 · answered by mak247mlh 5 · 0⤊ 0⤋
These are really simple. Check your textbook.
2007-12-26 10:46:27 · answer #6 · answered by Geno 3 · 0⤊ 0⤋