$20×.25=$5
$20-$5=$15
$15×.15=$2.25
$15+$2.25=$17.25
$17.25 is your answer
Given is a sculpture that is built up of metal and wood, and the weight of this sculpture is 14.9 kilograms.
It says that three-fourth of the total weight is metal and says to find the weight of wooden part.
We can find the weight of metal part and then subtract it from the total weight to calculate the answer.
Total weight = 14.9 kilograms.
Metal part = three-fourth of total weight = 
Wooden part = 14.9 - 11.175 = 3.725 kilograms.
Hence, the wooden part is 3.725 kilograms.
Some basic formulas involving triangles
\ a^2 = b^2 + c^2 - 2bc \textrm{ cos } \alphaa 2 =b 2+2 + c 2
−2bc cos α
\ b^2 = a^2 + c^2 - 2ac \textrm{ cos } \betab 2=
m_b^2 = \frac{1}{4}( 2a^2 + 2c^2 - b^2 )m b2 = 41(2a 2 + 2c 2-b 2)
b
Bisector formulas
\ \frac{a}{b} = \frac{m}{n} ba =nm
\ l^2 = ab - mnl 2=ab-mm
A = \frac{1}{2}a\cdot b = \frac{1}{2}c\cdot hA=
\ A = \sqrt{p(p - a)(p - b)(p - c)}A=
p(p−a)(p−b)(p−c)
\iits whatever A = prA=pr with r we denote the radius of the triangle inscribed circle
\ A = \frac{abc}{4R}A=
4R
abc
- R is the radius of the prescribed circle
\ A = \sqrt{p(p - a)(p - b)(p - c)}A=
p(p−a)(p−b)(p−c)
They are both simple exercises in addition.
The solutions are:
(-65) x (-2) = <em>130</em>
(5j) + (10j) =<em> 15j</em>
