Answer:
Given: BD is an altitude of △ABC .
Prove: sinA/a=sinC/c
Triangle ABC with an altitude BD where D is on side AC. Side AC is also labeled as small b. Side AB is also labeled as small c. Side BC is also labeled as small a. Altitude BD is labeled as small h.
Statement Reason
BD is an altitude of △ABC .
Given △ABD and △CBD are right triangles. (Definition of right triangle)
sinA=h/c and sinC=h/a
Cross multiplying, we have
csinA=h and asinC=h
(If a=b and a=c, then b=c)
csinA=asinC
csinA/ac=asinC/ac (Division Property of Equality)
sinA/a=sinC/c
This rule is known as the Sine Rule.
A. Area of given figure = 280 + 77 = 357 cm²
B. length of semicircle = 22 cm
Which pair shows equivalent expressions?
A.2(2/5x + 2)=2 2/5x + 1
B.2(2/5x + 2)=4/5x + 4
C.2(2/5x + 4)=4/5x + 2
D.2(2/5x + 4)=2 2/5x + 8
Solution:
Let us distribute 2 inside the parenthesis.
That is, we use distributive property:
a(b+c)=ab+ac
So, 
Answer:Option (b)
Applying distributive property, a(b+c)=ab+ac
So, Option (B) is correct.
The trick to solving problems with mixed units is to convert all of them into one unit or another, so:
There are 12 inches in a foot, so 72 inches = 6 feet.
To find the perimeter of a polygon, sum its sides.
Perimeter = 2 + 5 + 6 = 13 feet.
To find the area of a right triangle (which I assume the one in the picture is), we can use the following equation: A = 0.5 * base * height
There are 3 feet to one yard, so 6 feet = 2 yards.
Area = 0.5 * 2 * 1 = 1 yard^2
