Answer:
(a) AD=6 cm
(b) 66 cm²
(c) 38 cm
Step-by-step explanation:
(a) To get the length of AD, we can use pythagoras on the triangle part. Let's say the dotted line intersects DC at E. Then since AB and DC are parallel, AD is equal to BE. EC = 8 cm simply by subtracting AB from DC (15-7=8).
Then pythagoras says that 8²+BC²=10². So BC = √(100-64) = 6. And since BC=AD, AD is also 6.
(b) Area of the rectangle DEBA is 7*6 = 42. Area of triangle ECB is base times half height: 8*3 = 24. Sum is 42+24 = 66 cm²
(c) Perimeter is 7+10+15+6 = 38 cm. Add all the side lengths.
Answer:
He ran 3.25 on Tuesday
Step-by-step explanation:
The answer is 3.25 because 5.55 minus 2.3 is 3.25.
Using pythagorean theorem:
![\begin{gathered} c^2=a^2+b^2 \\ b=\sqrt[]{c^2-a^2} \\ b=\sqrt[]{19^2-17^2} \\ b=\sqrt[]{72} \\ b\approx8.5 \end{gathered}](https://tex.z-dn.net/?f=%5Cbegin%7Bgathered%7D%20c%5E2%3Da%5E2%2Bb%5E2%20%5C%5C%20b%3D%5Csqrt%5B%5D%7Bc%5E2-a%5E2%7D%20%5C%5C%20b%3D%5Csqrt%5B%5D%7B19%5E2-17%5E2%7D%20%5C%5C%20b%3D%5Csqrt%5B%5D%7B72%7D%20%5C%5C%20b%5Capprox8.5%20%5Cend%7Bgathered%7D)
D
Divide the whole thing by 2
2(X^2+8x-5)
X^2+8x. =5
Half of 8 is 4 sq it so you add 16
X^2+8x+16= 5+16
(X+4)^2=21
